Toronto plunges into lengthiest cold stretch in years as chill takes over Ontario

The hot weather records broken over the past few seasons in Toronto feel like a thing of the distant past during this first week of 2025, with temperatures taking a nosedive for what may prove to be the longest stint of sub-zero weather in multiple years.

Meteorologists projected in the fall that winter was due to “redeem its reputation” across the country this year, and it seems off to a decent start in Ontario, walloping areas from just north of GTA to cottage country with dozens of centimetres of snow in December.

While Toronto hasn’t seen too much in terms of accumulation, the city is in the midst of a deep freeze that The Weather Network forecasts to be the biggest in at least three years if the current patterns, which include a wind chill in the minus double digits, persists.

“The focus of the coldest weather in the country has quickly shifted into Central Canada from the eastern Prairies. In fact, the second week of January will be the coldest seven-day stretch of the season across the Great Lakes region, with the much colder-than-normal weather even extending all the way to Florida,” the agency wrote Monday night.

“For Toronto’s Pearson International Airport, we are looking at the possibility of its longest stretch of below-freezing temperatures in at least three years, perhaps more.”

Environment and Climate Change Canada’s (ECCC) forecast for this week calls for temperatures to feel as brutal as -24 C downtown on Wednesday with a chance of light snow, though thermometers will hover around a warmer (but still not enjoyable) -9 C.

The mercury will rise to around -2 C by the week’s end, but it will still feel colder: around -8 C Friday, -11 C Friday night, -5 C on Saturday and -10 C on Saturday night.

These conditions are thanks to a polar vortex that has partially settled over Hudson Bay, bringing with it “frequent shots of Arctic air and an abundance of lake-effect snow for parts of the Great Lakes region,” says TWN, leading to the longest spell of consecutive days below zero since January 2022.

If it continues longer than 12 days total, it will be the city’s most prolonged period below the 0 C mark since February 2021, which boasted a period of 16 days.

Though the lengthiest bout of such glacial weather in a number of years may sound concerning, it can actually be seen as quite the opposite given the abnormally — really, worryingly — warm months the city saw in 2023 and 2024.

“The big issue is the fact that we’ve had a string of very warm months, winter months, and we’re not used to it. The last month that was marginally colder than average was November of 2023. We’re not used to the fact that it can be — that it usually is — cold in the wintertime,” ECCC Meteorologist Peter Kimbell told blogTO over the phone on Tuesday.

“It shouldn’t be surprising that it’s cold because it is January, after all. We’re really just seeing something that’s closer to normal, and we’re not actually much below normal.”

This freeze reaching from western Manitoba to eastern Quebec is expected to let up in Southern Ontario by the latter half of January, per TWN’s outlook for the month, and is not expected to bring much in terms of winter storms — something that could change when temps warm in the coming weeks, as “the transition from cold to a milder pattern could actually bring the highest impact winter weather of the season.”