Potentially record-setting heat in store for Toronto

A heat warning remains in effect for the GTA, including Toronto, on what is expected to be the hottest day of the year so far.

Environment Canada issued the warning for the region on Monday, and Toronto’s medical officer of health issued a heat warning for the city on Tuesday.

“[Wednesday] will again see maximum temperatures in the low thirties,” the national weather agency said. “However, humidity levels will increase bringing humidex values to near 40.”

Overnight temperatures will still be warm, ranging between 20-23 C, Environment Canada said.

A mix of sun and cloud is in store on Wednesday with a chance of showers or thunderstorms, 680 NEWS meteorologist Jill Taylor said. The high will be 34 C with a humidex a sweaty 43. The expected low is near 22 C under partly cloudy skies.

Toronto could potentially break two temperature records on Wednesday. It could be the hottest July 13 on record, breaking the current record of 34.9 C set on this date in 2005 at Pearson.

It could also be the warmest day so far this year – 34.6 C was recorded on June 20. And, the UV index on Wednesday could potentially be the highest it has been all year.

Meanwhile, the potentially record-setting heat is already threatening to slow down the commute for GO Transit passengers. Transit officials plan to issue a “slow order” for its trains as a safety precaution, as tracks can sometimes bend under the hot temperatures.

Metrolinx said the slowdown is expected to add five to 10 minutes to the average train ride and up to 15 minutes or more on others.

Environment Canada said the hot weather will continue into Thursday with temperatures soaring once again to the low 30s. Taylor said it will feel more like 40 C with the humidity.

The humidity will give way to scattered showers and thunderstorms on Thursday, and Taylor said the storms could be severe at times.

With files from The Canadian Press