Toronto has a new July rainfall record of 193.2 millimetres after 11 millimetres of rain fell on the city Wednesday.
That beats the former record of 182.3 millimetres set in 1980.
David Phillips, a senior climatologist at Environment Canada, said that a jet stream that usually spends the summer over northern Quebec is most likely to blame for the high amount of rain.
"It's found southern Ontario more to its liking," Phillips told CTV.ca. "So we're just seeing a lot of storms coming in and hooking a ride on the jet stream and every day presents you with some more weather."
Phillips said that Toronto is only 32.3 millimetres shy from having its wettest summer on record.
The current summer record, which encompasses June, July and August, is 335.9 millimetres of rain set in 1986.
"The normal amount of rainfall in August would be about 80 millimetres," Phillips said. "So there's a really good chance that this will be clearly the wettest summer on record."
In fact, Toronto is having its wettest year so far, as 654 millimetres of snow and rain fell between January 1 and July 30.
Phillips said he guessed that this year would see more rain and snowfall given that last year was one of the driest years on record.
"What surprises me is the fact that it's been such a difference from last year," Phillips said. "I mean, nobody would have predicted this amount of rain."
Lightning damages homes
Meanwhile, lightning damaged several homes in the city's east end during Wednesday's storm.
Firefighters said lightning struck the chimney of John Kaklamanos' home on Magnolia Avenue, near Danforth Road. The bolt then travelled down through the house, through the underground plumbing and ended up inside a basement laundry room three homes away.
"I heard a huge bang, as if somebody dropped a bomb on something," Terrence Bascom, who lives in the home where the laundry room was damaged, told CTV Toronto.
The bolt caused a spark, and clothes and other property went up in flames.
The lightning destroyed the chimney at the Kaklamanos home, and sent pieces of bricks raining down onto his neighbour's roof.
The Kaklamanos family was advised not to stay in their house on Wednesday as there could be some structural damage to other parts of the home.
With a report from CTV Toronto's Tom Hayes
