Two major summer storms helped propel Toronto's Pearson International Airport to its wettest year on record, Environment Canada said.
According to meteorologist Steven Fleisfeder, the airport weather station recorded 1,145 millimeters of rain in 2024.
This eclipses the previous annual record set in 2008 by nearly 100 millimeters, and surpasses the 30-year norm by 300 millimeters.
Fleissfeder said once-in-a-century storms in both July and August brought more than 100 millimeters of rain to the airport station.
The Insurance Bureau of Canada, a national industry association, says more than $1 billion in insured losses occurred in Ontario, making it the second costliest summer for flooding in the province after 2013.
Fleissfeder said a station in downtown Toronto was only badly affected by the July storm, and ended the year with above-normal rainfall totals but below the annual record.
He says much of the province is near or slightly below normal rainfall levels compared to the 30-year average from 1991 to 2020.
Some areas east of Lake St. Clair in southwestern Ontario were above normal but “didn't break any records,” Fleisfeder said in an interview Friday.
He said it shows how severe summer weather can be “very localized”.
“We're seeing similar things with the snow squall activity that's currently happening in areas southeast of Georgian Bay, where areas near Barry have gotten up to 50 or 60 centimeters of snow so far, and areas 10,15 kilometers north have only received any snow. Snow,” he said. .
The storms in July and August each had a 100-year return period, Fleischfeder said, or a one percent chance of occurring in a given year.
It's “very rare” to see storms of that magnitude in recent months, Fleischfeder said, but it's happening with increasing regularity.
He said the record-setting results at Pearson reflect the effects of both El Niño and climate change.
El Niño, a natural recurring climate cycle in which warm water moves into the Pacific Ocean, typically increases summer rainfall for southern Ontario. Climate change, driven by the burning of fossil fuels, is characterized by a warmer climate that is able to hold more moisture that comes down in heavy rains.
