Canada’s 10 most impactful weather stories of 2024

Introduction

The weather of 2024 shattered records as Canada's most expensive year for weather disasters, with extreme events affecting millions of lives. From floods and damaging hail to extreme temperatures and devastating wildfires, these severe weather events left an unprecedented mark on both communities and insurance ledgers. According to Catastrophe Indices and Quantification Inc (CatIQ), four weather events in July and August alone resulted in over $7.7 billion in insured damages. The human toll was equally severe, with a brutal cold snap in January claiming dozens of lives in western Canada's homeless population, while flooding events in British Columbia, Quebec, and Nova Scotia added to the year's fatalities.

Extreme weather events increase with climate change

Alberta experienced four of this year's most impactful events, including another destructive hailstorm in Calgary that caused $2.8 billion in insured losses. This was Canada's costliest weather event in 2024 and the second-costliest overall in our nation's history. While the rising cost of events like these partly reflects our expanding communities and increasing property values, there's a deeper story at play: climate change is accelerating far beyond natural rates, due to human influence. Climate change is, intensifying both the frequency and severity of certain kinds of extreme weather events.

Extreme heat events are becoming much more likely. Results from the Rapid Extreme Weather Event Attribution system show that the heat that scorched the Maritimes in June, western Canada in July, and parts of the Arctic in August was made much more likely by human influence on the climate. In the case of Canada's Arctic, this summer's hottest heat waves were made at least 10X more likely by human caused climate change.

These extreme temperatures also increased wildfire risk, bringing hot, dry conditions that contributed to the intensity of the wildfires in Labrador, Newfoundland and Jasper, Alberta, that destroyed over 30 per cent of the iconic Rockies town.

Extreme rainfall events, like the atmospheric rivers that struck British Columbia, or the severe urban flooding caused by thunderstorms in Toronto and by the remnants of tropical cyclones in Montreal this year, are becoming more likely. As our atmosphere warms, more moisture can become available to feed these storms, increasing the potential for heavy rainfall and excessive flooding.

Nowhere are these changes more dramatic than in the Canadian Arctic, which is warming about three times faster than the global average, with significant impacts on Arctic communities. In September 2024, the Canadian Arctic reached its second-lowest ice coverage on record. By late that month, the northern route of the Northwest Passage saw its lowest ever ice coverage, becoming nearly ice free.

Human-caused climate change is increasing extreme weather, and its impacts are being felt now. Along with cutting greenhouse gas emissions, Canada must continue to act and adapt to make communities more resilient to these events.

1. From heatwave to wildfires: Jasper's summer inferno

July was exceptionally hot and dry in Jasper National Park.

Skies withheld much needed rain as daytime temperatures soared well above 30 °C on many days throughout the month. Drought conditions worsened as the park's vast wildlands and pine forests baked under the relentless heat. By July 21, the mercury reached a sweltering 38 °C. The fire danger index escalated to extreme, and forests became easy to ignite.

Strong thunderstorms developed on the evening of July 22, with powerful lightning bolts flashing as the storms swept through the park. The first wildfire was spotted late in the afternoon, just a few kilometres northeast of the Jasper townsite, followed shortly by a second wildfire several kilometres to the south.

By 9:59 p.m., the entire national park was under an evacuation order as wildfires spread rapidly, resulting in the closing of highways south and east of Jasper. Nearly 5,000 residents and the town's 20,000 visitors were forced to flee westbound on Highway 16—the only remaining escape route—toward British Columbia. Gridlock ensued, with ash falling onto vehicles and the southern skies glowing an eerie orange.

The next day, on July 23, the southern fire surged in size, fuelled by strong winds that pushed it through vast forest canopies and up entire mountain slopes. Billowing columns of copper-tinged smoke rose high above the Rocky Mountains.

Then came July 24. By late afternoon, gusty winds caused the southern fire to suddenly intensify and begin racing toward the townsite. Firefighting crews unsuccessfully fought to contain the blaze as its behaviour grew increasingly erratic and extreme. Forced into retreat, the firefighters could only watch as an unstoppable wall of flames breached the southern outskirts of town just before 6:00 p.m., launching fire balls hundreds of feet above trees.

The wildfire was so intense that it generated its own thunderstorm. Lightning flashes were detected several kilometres northeast of the fire, where smoke had blackened skies to the point that streetlights turned on in the town of Hinton, some 66 kilometres away. By 6:40 p.m., the fire began to move into the Jasper townsite. Showers of flaming debris were scattered across the town as toxic smoke filled the air. Firefighters worked tirelessly to protect critical infrastructure and put out new fires as they emerged. Only firefighters fitted with specialized breathing equipment could stay to battle the fire. Distressing images of iconic buildings burning started to surface on social media, causing many to speculate about the fate of the town.

While 12 millimetres of rain finally fell the next day, it was too little too late. A charred landscape of blackened sticks was all that remained of the forests that stood to the south and east of the town only a day earlier. The smell of musty smoke hung in the air above structures that had been reduced to ashes, with only brick chimneys left standing.

By July 25, the two fires merged. Evidence of significant wind damage later emerged near the Wabasso campground, just south of Jasper. A swath of mature forest was levelled, scrap metal was wrapped around trees, and a 6,700-pound, 20-foot sea container had been thrown over 100 metres into the nearby river. The suspected cause was an intensely rotating column of air generated by the fire itself.

The wildfire claimed 358 of the town's 1,113 structures, including many homes, the iconic Maligne Lodge, and a nearly 100-year-old church. The tireless efforts of fire crews undoubtedly saved many more buildings. No critical infrastructure was lost, and the early evacuation of the town's residents and visitors was credited as a notable success.

Tragically, a wildland firefighter lost his life on August 3 while battling the fire.

According to Catastrophe Indices and Quantification Inc (CatIQ), insured losses from the fire reached $880 million, making it the second-costliest wildfire disaster in Canadian history. It joins a growing list of significant wildfire events impacting Alberta communities in recent years, surpassing the $700 million Slave Lake fire of 2011, and trailing only the $4.5 billion Fort McMurray wildfire of 2016.

By the time the Jasper Wildfire Complex was finally declared under control on September 7, it had consumed 32,722 hectares of forest in Jasper National Park, an area spanning wider than the island of Malta. As one of Canada's national treasures and the Canadian Rockies' largest national park, Jasper will bear the scars of this wildfire event for years, leaving parts of its landscape forever changed.

2. Central Canada bears the brunt of the 2024 hurricane season

In Canada, the impacts of tropical cyclones tend to be felt most strongly in the Atlantic provinces. This year, however, central Canada bore the brunt of the activity, as the remnants of two tropical cyclones caused significant flooding across parts of the region.

Beryl

On July 2, Beryl became the first ever Atlantic hurricane to attain a Category 5 intensity so early in the season, packing sustained winds of up to 270 km/h as it moved westward into the Caribbean Sea near Grenada. By July 8, the system had weakened to a Category 1 hurricane when it made landfall along the Texas Gulf Coast, with maximum sustained winds of nearly 130 km/h. After moving inland, Beryl transitioned into a post-tropical low-pressure system, triggering flooding and several tornadoes as it moved quickly northward across the United States.

Although it had lost its tropical cyclone characteristics, the remnant storm system remained loaded with moisture. By July 10, it reached southern Quebec, bringing thunderstorms with torrential rain across Greater Montréal. Between 50 and 100 millimetres of rain fell within a few hours, causing widespread flash flooding throughout the region.

Muddy floodwaters inundated roads and underpasses in parts of Montréal, including the busy Décarie Expressway, where several motorists were stranded in their vehicles. Throughout the city, sewers backed up, basements filled with water, and numerous businesses were flooded. Workers at one warehouse were forced to swim through cold, murky waters to reach drier ground. Up to 12,000 customers lost power on the afternoon of the 10th, mainly in the Montréal and Montérégie areas.

Beryl's remains moved into the Maritimes on July 11, unleashing a deluge across parts of Nova Scotia. The Annapolis Valley region was hit the hardest, where up to 130 millimetres of rain fell over a few hours, causing damage to roads and a bridge. Tragically, a boy from Wolfville lost his life after being swept into a water-filled ditch.

Nearly a month later, remnants of Tropical Storm Debby would trigger another round of destructive flooding.

Debby

Debby initially made landfall as a hurricane in northwestern Florida before tracking through the southeastern United States to a second landfall in South Carolina. After moving inland, it transitioned into a post-tropical low-pressure system, generating flooding rains, damaging winds, and tornadoes as it moved northward across the eastern United States. On August 9, the system arrived in central Canada.

By early morning, the skies opened up over eastern Ontario and southern Quebec, delivering heavy downpours on and off throughout the day. Between 80 and 120 millimetres of rain fell across the National Capital Region, creating torrents of water that damaged roads and washed some out completely. Areas just west of Ottawa were particularly affected, with hundreds of basements flooded in West Carleton. In Akwesasne, just south of Cornwall, the Saint Regis Mohawk Tribe also reported flooded roads and basements.

Meanwhile, across southern Quebec, drenching rains caused significant problems. Over a 24-hour period, between 100 and 200 millimetres of rain fell along, and north of, the heavily populated St. Lawrence River Valley. Severe impacts occurred from the Outaouais region to the Eastern Townships, including Greater Montréal, the Laurentians, Lanaudière, Mauricie, Montérégie, and Centre-du-Québec.

A substantial 154 millimetres of rain fell at Montréal International Airport on August 9, setting a new all-time high daily precipitation record. Motorists were stranded on flooded roads in parts of the city, with some requiring rescue by boat. The greatest rainfall accumulation of the day was recorded in the municipality of Lanoraie, about an hour drive northeast of Montréal, with 221 millimetres.

More than 1000 homes were flooded across southern Quebec. The soaking rains caused slopes to slump and slide, while flash floods damaged 170 roads. Tragically, in the Mauricie region, a man lost his life when a roadway collapsed, plunging him into the Batiscan River. As the storm system departed, wind gusts as high as 95 km/h swept through the region, cutting power to 550,000 customers.

Flooding from Debby the costliest disaster in Quebec history

The 2024 Atlantic hurricane season started out slowly but ended up trending moderately above average across the basin. While no tropical cyclones directly impacted Canada, the waterlogged remnants of Beryl and Debby were another reminder that these storms can remain highly impactful long after losing their tropical characteristics.

The August 9 to 10 floods across southern Quebec became the province's costliest weather disaster, with insured damages reaching an estimated $2.5 billion, according to Catastrophe Indices and Quantification Inc. (CatIQ). This surpassed the cost of the long-standing ice storm of 1998, which caused roughly $2.4 billion damage in today's dollars.

3. Western Canada plunged into January deep freeze

What happens in the Arctic doesn't always stay in the Arctic.

Every winter, air masses sitting over the dark, frozen expanses of the North become bitterly cold. Sometimes, shifting atmospheric wind patterns can cause these air masses to move further south, causing significant problems in more heavily populated areas.

In mid-January, a particularly frigid Arctic air mass slid southward into western Canada, causing a reversal in temperatures from north to south. Some areas of Canada's Arctic saw unusual warmth, with winter rainfall and temperatures above freezing causing water to pool on snow and ice in eastern areas of Nunavut. Meanwhile, parts of British Columbia, Alberta, and Saskatchewan endured an Arctic chill not felt in decades.

Temperatures plunged as low as the minus 40s across parts of Canada's three westernmost provinces, with the coldest wind chills dipping below minus 50. Between January 11 and 15, over 60 daily minimum temperature records were broken across British Columbia. Alberta saw about 125 daily minimum temperature records, including eight all-time cold records broken between January 10 and 17. Saskatchewan saw nearly 25 daily minimum records and one all-time cold record broken.

British Columbia's coldest temperature of the event occurred in the Cariboo region, at Puntzi Mountain, where a new daily record of -48.4 °C was set. Temperatures also bottomed out around –48 °C at several weather stations in central and northern Alberta, with Saskatchewan's coldest temperature dropping to –46 °C at Leader Airport.

The Coast Mountains of British Columbia acted as a dam to the frigid air mass that had pushed its way southward into the interior, keeping the coldest air temperatures from reaching the shores of the Pacific. But the dense, higher-pressure air breached the mountain chain through gaps like the lower Fraser Valley and Howe Sound, bringing Arctic outflow winds with gusts of 60 to 80 km/h to the coast. Bitterly cold wind chills even reached Vancouver's palm tree-lined waterfront, with exposed areas of the South Coast region experiencing wind chill values as low as minus 30.

Impacts from the cold were significant and widespread. Over 500 flights were cancelled across western Canada throughout the cold snap, as airport equipment and de-icing fluid stopped working and airline operators limited the time that ground crews could work outside in the dangerous cold. In Alberta, motorists in need of roadside assistance faced wait times of over 96 hours for battery boosts, tows, and winches. Between January 9 and 17, the Alberta Motor Association received over 49,000 calls for assistance—one of their busiest periods ever in its nearly 100-year history.

Multiple ski resorts across western Canada closed as the extreme cold increased the risk of hypothermia and frostbite. In the Calgary area, several schools cancelled classes and bus services on January 12, and in Siksika Nation, a State of Local Emergency was issued when a gas service outage left residents of more than 50 homes unable to use their furnaces.

The cold didn't spare the fruit trees and vineyards of British Columbia's Okanagan Valley – an area known locally as the fruit basket of western Canada. In Kelowna, temperatures plummeted to –30 °C on the morning of January 13, while Penticton hit an all-time record low of -27.6 °C. Following a warm start to winter, delicate buds had appeared on the trees by early January, but froze in the extreme, mid-month cold. This caused devastating losses of stone fruits for the year, including peaches, apricots, and plums. Wine grapes and cherry crops also took a significant hit, causing hundreds of millions of dollars in lost revenue for wine and fruit industries. Farmers were forced to plant other kinds of crops for the year.

Burst pipes and broken heaters wreaked havoc in buildings and hospitals around western Canada. In British Columbia, the Mission Memorial Hospital closed their emergency department after a burst pipe caused flood damage, and the temperature in the waiting area at the Royal Inland Hospital in Kamloops fell to -6°C after a heater broke. In Alberta, Edmonton's Royal Alexandria Hospital was forced to divert patients to other hospitals after its emergency department and waiting room lost heat. In Saskatoon, burst sprinkler lines caused flooding in the main entrance and basement of the St. Paul's Hospital, and in Regina, City Hall also had to close because of a burst pipe.

The frigid temperatures caused tremendous strain on the western Canadian power grid. On the evening of January 11, Alberta set its all-time provincial record for power demand, and on the evening of the 12th, British Columbia did too. On January 13, an emergency alert was issued in Alberta, urging residents to reduce power consumption to avoid rotating power outages. It was the first ever emergency alert of its kind in the province, successfully prompting Albertans to act immediately. The cold also had a significant impact on homeless populations across western Canada. British Columbia attributed 36 deaths to the cold in the first two weeks of January, and Alberta emergency rooms filled with cold-related illnesses throughout the cold snap.

The multi-day extreme cold event resulted in approximately $180 million in insured losses across British Columbia, Alberta, and Saskatchewan, primarily from water damage caused by frozen and burst pipes, according to Catastrophe Indices and Quantification Inc. (CatIQ). While 70 per cent of claims were for personal property damage, the event's impacts extended across multiple sectors – from widespread infrastructure challenges and agricultural losses to significant strain on emergency and healthcare services. The event highlighted the resilience of western Canadians and underscored the far-reaching impacts of Arctic weather systems, reminding us that what happens in the Arctic doesn't always stay there.

4. Atmospheric rivers deliver double blow to British Columbia

As storm systems swirl across the Earth's mid-latitudes, they transport heat and moisture from the tropics toward Earth's polar regions. Some of these storms create long narrow flows of moist air that travel thousands of kilometres—like great rivers in the sky. Known as atmospheric rivers, these airflows can produce heavy precipitation, particularly where they are forced up mountain slopes.

Each year, about 30 to 40 atmospheric rivers reach coastal British Columbia, typically delivering beneficial precipitation that replenishes mountain snowpacks and water supply. However, when they are strong, long-lasting, or occur in succession, their effects can become more hazardous than beneficial, triggering dangerous flooding.

In 2024, atmospheric rivers contributed to dangerous flooding, deadly landslides, and road washouts across southwestern British Columbia in both January and October.

January 26 to February 1

Toward the end of January, a series of Pacific storms brought widespread heavy rain to southwestern British Columbia, fuelled by several atmospheric rivers. Repeated rounds of rain saturated the ground, causing water from later rounds to rapidly run off, leading to flooding. Between January 26 and February 1, over 200 millimetres of rain fell over the higher terrain in parts of British Columbia's South Coast region.

When atmospheric rivers, like those of late January, tap into Pacific moisture originating near the Hawaiian Islands, they are known as “Pineapple Express” storms. These events produce heavy precipitation and bring warm temperatures, with freezing levels rising above mountain heights. This can result in rain falling on mountain snowpacks, leading to rapid melt and runoff and swelling downstream rivers.

On January 30, the village of Pemberton, located 150 kilometres north of Vancouver, declared a Local State of Emergency when flooding led to several property evacuations. The heavy rains prompted flood warnings for the Squamish, Sumas, and Lillooet Rivers. A stretch of Highway 1 through the steep-sided Fraser Canyon north of Lytton was closed due to flooding and debris on the road. In parts of the Fraser Valley near Abbotsford, agricultural lands were covered with water.

Heavy rain and warm temperatures exposed grass and dirt on the ski hills of the North Shore Mountains, melting the snowpack and closing all three ski resorts in Metro Vancouver. Throughout British Columbia and Alberta mountains, the warm and wet conditions significantly increased avalanche danger.

During the last week of January, the unusually mild Pacific air mass broke over 100 daily high-temperature records across British Columbia. The air mass further warmed and dried as it descended eastward into the prairies, causing rapid snowmelt and record-breaking temperatures that soared from 10 to 20°C, or more, above normal.

October 18-20

On the weekend of October 18 to 20, an atmospheric river impacted southwestern British Columbia, tragically claiming five lives in its wake. The storm brought high winds that disrupted ferry service and downed power lines throughout the region. Southern Vancouver Island and densely populated areas of the Lower Mainland were hardest hit, with high winds and flooding rain causing temporary closures and additional problems as voters headed to polling stations for the October 19 provincial election.

Daily rainfall records fell across the region, with many weather stations around Metro Vancouver recording over 100 millimetres on the Sunday, October 20 alone. By the weekend's end, West Vancouver had received 203 millimetres, while Coquitlam recorded a staggering 256 millimetres. But it was Kennedy Lake on Vancouver Island that recorded the highest multi-day total, with a soggy 318 millimetres.

Torrents of muddy water cascaded over roadways in communities near the North Shore Mountains, where many homes and basements were flooded. Tap water turned cloudy throughout eastern sections of the metro region, after upstream reservoirs filled with murky mountain runoff. Agricultural lands near Abbotsford and in parts of the Fraser Valley again suffered flooded fields and buildings.

Tragedy struck in Coquitlam, where two people lost their lives. On the 19th, a local teacher died when a mudslide swept her home off its foundation, and on the 20th, a man died after falling into the Coquitlam River while walking his dog. On Vancouver Island, two more people died in separate incidents while driving on a flooded road next to the Sarita River, near Bamfield. Adding to these tragic losses, a hiker also passed away along a trail on Grouse Mountain.

While these atmospheric rivers brought destructive flooding and tragic loss of life, they also highlighted the complex nature of these weather systems in British Columbia's climate. The same intense rainfall that caused widespread damage helped alleviate severe drought conditions throughout coastal, central, and southern British Columbia, demonstrating how these powerful weather phenomena can be both destructive and vital to the region's water cycle.

Starting in 2025, ECCC will also be able to use its Rapid Extreme Weather Event Attribution system to analyze the connection between human-caused climate change and the odds of experiencing extreme precipitation events including snow and rain.

5. Billion-Dollar hailstones: Calgary's costliest weather disaster

Residents of Alberta's “Hailstorm Alley” are no stranger to destructive thunderstorms, with the city of Calgary being widely recognized as the hail capital of Canada. Less than five years after the last billion-dollar weather event in the city, another devastating hailstorm in early August caused even greater damage.

On the evening of August 5, two intense, rotating thunderstorms erupted along the southern Alberta foothills and moved southeast toward the Calgary region. The southern storm dropped baseball-sized hail as it plowed through rural lands southeast of the city, while the northern storm battered thousands of homes and vehicles across Calgary's northern suburbs.

The hailstorm of June 13, 2020, at the time, was thought to be as bad as it could get, but in August, storm-weary residents in parts of the city's northeastern quadrant experienced déjà vu as wind-driven chunks of ice, up to the size of hen eggs, caused new destruction. Menacing black clouds unleashed a frightening barrage of hailstones. Driven by strong winds, the ice chunks blew in sideways, punching holes in vinyl siding and destroying roofs. Videos captured hailstones smashing through windows and landing on living room floors. Cars parked outside looked as if they had been pelted with a hammer, with shattered glass and caved-in windshields.

The storm then swept over Calgary International Airport, where a cascade of icy stormwater poured through a terminal roof. Numerous flights were cancelled and ten per cent of one airline's fleet was grounded for several weeks due to severe damage. Elsewhere, torrential rains from the storm caused localized flooding, and copious hail chilled the air as it painted the landscape as white as winter. Nearly one in five Calgary homes was impacted by the storm, resulting in almost 130,000 insurance claims. More than half of these claims were for vehicles, many of which were write-offs.

After leaving the city of Calgary, the storm moved southeast, carving a swath through maturing crops, known by prairie farmers as “the great, white combine.” The hail damage from both storms was so extensive that their tracks left scars on the land that were visible from space.

In total, the storm caused nearly $2.8 billion in damage, according to estimates from Catastrophe Indices and Quantification Inc (CatIQ). This ranks as the costliest hailstorm in Canadian history and the second-costliest weather disaster overall. The storm follows a trend of increasingly destructive hail events in Alberta, with insured losses totalling over $5.5 billion in the past five years alone.

As the footprint of cities like Calgary continue to expand, what was once a rural area become urban and more people are exposed to severe weather impacts, including destructive hailstorms. This has driven up the costs of insurance for Albertans living in Hailstorm Alley, prompting calls to find ways for residents to reduce damage to property.

6. Southern Ontario's summer of floods

It was a soggy summer in southern Ontario, with several bouts of heavy rain causing significant flooding across parts of the region. Two events particularly stood out, bringing widespread impacts to the Greater Toronto Area on both occasions.

July 15-16

Between July 15 and 16, numerous thunderstorms tracked across southern Ontario. Early on the morning of the 15th, the first cluster of thunderstorms entered southwestern Ontario from the state of Michigan. Several more rounds of storms rumbled their way eastward into the Golden Horseshoe region by the afternoon. In less than four hours, 50 to 60 millimetres of rain doused the London area, flooding roads and basements, and closing a stretch of Highway 402 west of the city. Further east, over 60 millimetres of rain fell over six hours in the Hamilton and Burlington areas, flooding homes, streets, and businesses. In downtown Toronto, 25 millimetres of rain fell in under one hour, flooding two subway stations along with parts of Lakeshore Boulevard.  And that was not the end of it.

On the morning of July 16, storms lined up across southern Ontario once again, but this time, they aimed squarely at the Greater Toronto Area (GTA). The ground was already saturated from previous downpours. When the storms began, the water had nowhere to go.

Most of the precipitation fell within just a few hours, triggering widespread flash flooding. The heaviest rain fell over parts of Mississauga and Toronto, with 97.8 millimetres filling the rain gauge at Pearson International Airport. Downtown Toronto recorded 83.6 millimetres of rain, and 87 millimetres fell at Billy Bishop Airport, located along the Toronto Waterfront.

Many multi-lane freeways, including the 401, 410, 404, 400, and 427, were flooded. In downtown Toronto, sections of Lakeshore Boulevard and the Gardiner Expressway were also under water. Calls for emergency services poured in as people were stranded on flooded roadways and trapped in elevators. Police, fire, and emergency medical services, along with Toronto Emergency Management, coordinated an impressive response.

The Don Valley Parkway, a major north-south route that snakes its way alongside the scenic Don River Valley and into downtown, is especially prone to flooding during heavy rainstorms. On July 16, dozens of vehicles became stranded when murky water covered sections of the roadway, leading to 12 water rescues.

Commuters downtown faced chaos as flooding turned staircases at Union Station into waterfalls, and nearby subway stations were closed as water surged into Toronto's underground transit system. At the same time, a significant power outage affected nearly 300,000 customers downtown and beyond for several hours.

In Mississauga, the fire department conducted multiple water rescues on flooded roads and over 100 residents of a nursing home had to be relocated. In the Kitchener-Waterloo-Cambridge area, flood-related calls surged as roads, trails, and parks were inundated. In the City of Kitchener, a section of railway tracks was left suspended in mid-air after the ground beneath it washed away in a rushing torrent of water.

By the time the rain ended, the floods of July 15-16 had caused over $940 million in insured damages across southern Ontario, according to Catastrophe Indices and Quantification Inc. (CatIQ).

August 17-18

Just weeks later, between August 17 and 18, a slow-moving low-pressure system brought another round of severe flooding to the region.

The trouble began on the morning of August 17, when a thunderstorm produced a damaging tornado just south of Kitchener in the town of Ayr. The tornado, rated EF2 on the Enhanced Fujita scale with winds over 180 km/h, toppled trees, damaged buildings, and tossed vehicles along its seven-kilometre-long track.

Then, thunderstorms bringing torrential rain moved into Mississauga and parts of Toronto. Once again, roads and basements were flooded in the area, with numerous people requiring rescue from stranded vehicles and stuck elevators. One person in Mississauga was rescued after clinging to a light post in a flooded intersection. Segments of major highways were flooded, including the 401, 403, and 410.

Toronto Pearson International Airport received a record-breaking 128.3 millimetres of rain in a single day, where flights were temporarily grounded, causing significant delays. Meanwhile, Billy Bishop Airport, less than 20 kilometres away, stayed dry, highlighting the often-isolated nature of thunderstorm rains.

In Mississauga, things went from bad to worse when more torrential rains impacted the city on the afternoon of the 18th, causing yet another round of flooding. Some motorists were trapped on Highway 410, where a local fire department deployed a small boat to free the occupants from several stranded vehicles.

The floods of August 17 and 18 across the GTA and surrounding regions caused over $100 million in insured losses, according to Catastrophe Indices and Quantification Inc. (CatIQ). This brought the combined cost of flood damage across the region to over $1 billion for the year, making it the second-costliest summer in Ontario history for weather-related damage after the Toronto floods of 2013.

7. Arctic communities face unusual heatwave

It's not often that temperatures over 30 °C make it all the way to the shores of the Arctic Ocean, but that's exactly what happened when a multi-day heat wave spread across parts of Canada's north.

During the first week of August, an upper ridgebegan to build into the atmosphere over northwestern Canada, causing sinking air, clear skies, and rising temperatures. As the ridge neared peak strength, temperatures climbed well above 30°C across much of the Northwest Territories, with the highest readings occurring between August 6 and 10.

More than 200 kilometres north of the Arctic Circle, where Canada's northernmost taiga forest meets the Mackenzie River Delta, lies the town of Inuvik. On August 6, 7, and 8, temperatures soared above 30 °C, which is over 10°C above normal highs for the time of year. The temperatures broke records and forced residents of the Northwest Territories' third-largest town to find creative ways to keep cool.

For relief from the heat, the Inuvik Fire Department created a pop-up water park for children by spraying water into the air, and for the first time ever, an emergency cooling shelter was set up at the town's curling rink. On August 7, the town recorded its highest temperature of all time at 34.8 °C. There was little relief at night throughout the heatwave, as the long daylight hours prevented buildings from cooling down. A few hours after the all-time high was reached, the temperature was still 27 °C at midnight.

Other towns north of the Arctic Circle also experienced record-breaking heat. On August 7, Aklavik hit 33.1°C, and on August 8, Fort McPherson set a new all-time high for the third day in a row, at 35.1°C. On the southern shores of the Arctic Ocean, the Inuvialuit community of Paulatuk hit an all-time high of 31.0°C on August 8. With no cooling systems in public buildings, many residents kept cool by swimming in nearby lakes.

A little further south, Tulita hit an all-time high of 34.6°C on August 8, while Fort Good Hope set all-time record highs for three days straight from August 7 to 9, hitting a sweltering 37.0°C on the 9th.

As the upper ridge gradually shifted southeast, the unusual Arctic heat moved along with it. Starting around August 6, peak temperatures soared 10 to 15 °C above normal in the southern parts of the Inuvialuit Settlement Region, spreading eastward across the Kitikmeot and Kivalliq regions of Nunavut, before easing after August 14.

The extreme heat increased fire risk across the Northwest Territories, which faced yet another active season of wildfire events in a year that was warmer and much drier than average. Of the over 5.3 million hectares of forest that burned in Canada in 2024, nearly one third burned in the Northwest Territories alone, at roughly 1.7 million hectares.

8. Cape Breton's winter wallop

Cape Bretoners are no stranger to winter storms, but the historic, multi-day snowfall of early February was different.

The trouble began when an intensifying low-pressure system stalled off the coast of Nova Scotia from February 2 to 5. Winter storm systems typically travel along with stronger winds higher in the atmosphere, but upper winds around this storm were notably weak, enabling it to become parked in one place. Drawing from a steady supply of moisture, the expanding storm system brought heavy snow and gusty northerly winds across Atlantic Canada for an extended period.

In Sydney, Nova Scotia, the snow kept coming. And coming. Between Friday, February 2 and Monday, February 5, a total of over 100 centimetres was reported in downtown Sydney, with 97.1 centimetres recorded at the airport.

In parts of Cape Breton, strong winds piled the snow into massive drifts, several metres deep. Incredible images circulated online, showing city streets buried in snow, with some residents forced to tunnel out of their homes as snow piled up against front doors. On the ground floor of one apartment, the pressure of the snow against the windows became so strong that they broke. Numerous motorists were stranded, with abandoned vehicles quickly disappearing under the heavy snow.

On Sunday, February 4, the Cape Breton Regional Municipality declared a State of Local Emergency, urging residents to shelter in place and stay off the roads. Help was brought in from surrounding provinces to clear snow-clogged roads, with some snowplows even becoming stuck while working to remove the snow.

The storm's impacts were not limited to Cape Breton; heavy snow blanketed much of central and eastern Nova Scotia, along with eastern Prince Edward Island, with 40 to 65 centimetres accumulating across most of the region. Winds were strongest near coastal areas, with gusts reaching 70-80 km/h. The strong winds reduced visibility to zero, disrupted Marine Atlantic ferry travel, and contributed to power outages affecting approximately 9000 customers, mainly in Nova Scotia.

Numerous businesses, schools, and services closed across Nova Scotia and Prince Edward Island on Monday. Postal service was suspended for the day and 70 flights were cancelled at Halifax Stanfield International Airport, which received over 80 centimetres of snow over the weekend. Halifax recorded its snowiest February of all time, and Sydney its third snowiest, amid an active winter marked by frequent storm systems across the eastern Maritimes.

The winter storm was the worst to hit this part of the Maritimes since “White Juan” – a powerful winter storm system in February 2004 that caused significant impacts in the region five months after destructive Hurricane Juan made landfall near Halifax. In the Sydney area, it was the largest multi-day snow event since the winter of 1992, when 102 centimetres fell at Sydney Airport from January 31 to February 4.

9. Summer split: Maritimes sizzle while Alberta shivers

It was a tale of two extremes across Canada when the third week of June rolled around.

In Atlantic Canada, a crescendo of hot, humid weather peaked between June 18 and 20, setting numerous daily, monthly, and all-time high temperature records. An unusually strong ridge of high pressure built in the atmosphere over eastern North America, causing sinking air and clear skies. These conditions allowed surface temperatures to climb well above 30 °C from parts of Ontario and Quebec to Atlantic Canada.

June 19

On June 19, Miscou Island in New Brunswick reached an all-time record high of 34.1 °C, while Miramichi (37.2 °C) in the same province and Ingonish in Nova Scotia (34.5 °C) set new monthly all-time high temperature records. Prince Edward Island, as well, saw its highest June temperature when the North Cape soared to 34.9 °C.

The highest temperature of the day, however, was recorded in Bathurst, New Brunswick, where the mercury hit a scorching 37.6°C. This was not only the station's highest temperature on record, dating back to 1872, but also the highest temperature ever recorded in New Brunswick and anywhere in the Maritimes for the month of June. These temperatures ranged from 10 to 15 degrees or more above seasonal values.

June 20

In Saint John, New Brunswick, the temperature hit an all-time record high of 34.5 °C on the 20th, while Halifax Airport set a new June record of 34.3 °C. Temperature records were also being set in Newfoundland and Labrador, with Terra Nova Provincial Park reaching 35.4 °C, tying its all-time record high. There was no relief from the heat across the Atlantic coast.

Schools without air conditioning across northern New Brunswick either closed early or cancelled classes for the day. Salmon pools along the Miramichi River were closed for fishing to protect the salmon as they sought refuge in cooler waters. One Fredericton-area restaurant kitchen made the decision to shut down for the day after workers said temperatures inside reached a toasty 60 °C.

Western Canada gets the cold shoulder

While eastern Canada endured stifling heat, western Canada was left out in the cold, with Alberta setting 46 daily record lows across the province between June 15 and 20. Sandwiched between two strong upper ridges, the jet stream buckled into a trough over the western prairies, bringing an unusually cool and dry air mass to the region. Despite the summer solstice approaching on June 21, the weather across southern Alberta felt more like “June-uary”.

The coldest temperatures came on the morning of June 17, with many weather stations in the mountains and foothills recording temperatures below zero. Jasper, Crowsnest, Sundre, and Cardston all recorded sub-zero temperatures, while Waterton Park plunged to an icy -4.8 °C. Frost warnings extended from Calgary to Edmonton and beyond, prompting gardeners to protect their plants. Newly sprouted pea and canola crops in parts of central Alberta suffered minor damage from the frost.

If the frost was not enough, snow would soon follow. On the morning of June 18, flakes flew from Crowsnest to Banff, with snow accumulating just west of Calgary. The heaviest snow blanketed the ranchlands just west of Nanton, where a whopping 30 cm of snow fell, bending fully leafed tree limbs toward the ground.

Starting this winter, ECCC will also be able to use its Rapid Extreme Weather Event Attribution system to analyze the connection between human-caused climate change and the odds of experiencing extreme cold temperature events.

10. Wildfires and evacuations in western Labrador

It was a summer on edge in western Labrador, as wildfires triggered the evacuation of entire towns on more than one occasion. Residents of Churchill Falls and Labrador City were among those forced to flee when wildfires began to burn a little too close to home.

Churchill Falls

June in Labrador was much warmer and drier than average. A particularly warm and dry stretch during the first half of the month dried out vegetation throughout the region's boreal forests, increasing the fire risk. Then, the lightning came.

On June 13, lightning ignited a wildfire several kilometres southwest of Churchill Falls, a town of about 750 residents and home of the second-largest hydroelectric power generating station in Canada.

Initially, cooler conditions kept fire growth minimal, but the heat soon returned. On June 19, the temperature soared to a record 32.6 °C in Churchill Falls, as a heat wave spread across most of eastern Canada. High temperatures and gusty southwest winds caused the fire to intensify, pushing it closer to Churchill Falls and prompting an evacuation order for the town.

Residents were directed 287 kilometres east, along the only connecting route toward Happy Valley-Goose Bay, as lightning flashed overhead. Many sheltered with family and friends upon arrival, while others stayed at the local YMCA.

The province issued a fire ban across Newfoundland and Labrador to focus firefighting resources on controlling the blaze, while a small crew of hydro workers remained in Churchill Falls to operate the power plant. The Labrador River to the south of town acted as a natural barrier to the fire's northward spread, as crews worked to contain it over the coming days. On June 25, however, warm and windy conditions drove the fire across the river, triggering the evacuation of the remaining hydro workers. The fire advanced to within 3 kilometres of the town before cooler and wetter conditions slowed its spread once again.

On July 3, two weeks after the evacuation order, residents were allowed to return home, but the threat was not over for western Labrador.

Labrador City

The warm and dry weather returned in early July, with lightning strikes sparking several new wildfires on July 8 and 9. One of these fires started a few kilometres west of Labrador City – the second-largest town in Labrador.

The fire initially smouldered harmlessly on the forest floor, but on July 12, a warm, dry wind changed everything. The fire travelled an astonishing 21 kilometres eastward in just four hours, growing aggressively from roughly 600 hectares to over 10,000 by the end of the day. An evacuation order for the entire town of over 7000 residents was issued at 5:30 p.m., with the population being once again directed east toward Happy Valley-Goose Bay.

More than 1,000 vehicles crawled eastward along the 529-kilometre trek across Labrador, passing through Churchill Falls near the halfway point, which had all too recently experienced its own evacuation. Long lines formed at the single gas station in town, which extended its hours to stay open all night to aid the travellers making the lengthy journey east. The influx of evacuees effectively doubled the population of Happy Valley-Goose Bay, which nonetheless rose to the occasion by providing food, shelter, and a place to sleep for anyone in need.

Merciful rains in the following days slowed the fire's spread, halting it just northwest of town. The evacuation order was lifted ten days later on July 22. Thanks to the swift and coordinated efforts of local authorities, first responders, and volunteers, the largest evacuation in the history of Newfoundland and Labrador was managed successfully, preserving lives and property.

Canada saw over 5.3 million hectares of forest burned in 2024, more than double the national average of 2.1 million hectares. These events reflect the escalating threat of wildfires across the country, with each season testing communities' resilience and adaptability.