Shocking temperature divide to carve across Ontario on Sunday

·2 min read
Shocking temperature divide to carve across Ontario on Sunday

Canada’s warmest air of the year will spread over southern Ontario on Sunday as some spots make a run at the 30-degree mark. While it’ll be a fabulous day across most of southern Ontario, folks near the lakeshores could find disappointment instead of delight. More on the continuing warmup, and how far temperatures will plummet next week, below.

SUNDAY: GET OUT AND ENJOY IT WHILE IT LASTS!

A warm front associated with the potent system bringing heavy snow and flooding rains to the eastern Prairies will sweep across southern Ontario overnight into Sunday morning.

ONSunday
ONSunday

The advancing warm front will lead to a period of fog for much of the region heading into the morning hours. Use caution if you’re out and about during the fog, as visibility can change quickly over short distances. Temperatures will warm up in a hurry through the day, allowing the fog to dissipate and clear skies to prevail.

Sunny skies, southeasterly winds, and an upper-level ridge will work together to allow temperatures to push into the mid- to upper-20s for much of interior southern Ontario. Some folks in far southwestern Ontario could crack the magical 30°C mark, notching Canada’s first such reading so far this year.

GHTA Lake Breeze
GHTA Lake Breeze

It’s going to be a story of the haves and the have-nots, unfortunately, as the cold waters of Lake Erie and Lake Ontario will keep many lakeshore communities remarkably chilly through the day.

We could see a 20°C spread over very short distances as a result of southeasterly winds blowing water-cooled air ashore. This is likely to affect the Golden Horseshoe, especially, where you could experience a sharp temperature gradient from one neighbourhood to the next.

MONDAY: A COLD FRONT CRASHES THE PARTY

It was nice while it lasted. For some areas, especially in southwestern Ontario, Monday is going to be one of those days where the high temperature occurs in the early morning hours.

ONMondayPrecip
ONMondayPrecip

The lingering warmth will come to an abrupt end as a cold front sweeps across southern Ontario from the west, sending temperatures falling through the day. Scattered showers will accompany the front as it traverses the province. We’ll see afternoon temperatures in the low- to mid-teens for much of the region.

TUESDAY AND BEYOND: THE GREAT COOLDOWN RETURNS

The upper-level ridge that brought us a warm weekend will move downstream heading into the new workweek, allowing an upper-level trough to take its place. This trough will bring much cooler air, making for chilly conditions by midweek.

InuvikLondon
InuvikLondon

Temperatures will come in up to 10°C below seasonal by Wednesday. In fact, the upcoming streak of below-seasonal air will put parts of southern Ontario on par with the Arctic Circle. London and Inuvik will both expect a high of about 2°C on Wednesday.

This spell of below-seasonal conditions looks to continue through the beginning of May.

Thumbnail courtesy of Getty Images/LFO62 Creative #: 1147294367.

Stay with The Weather Network for the latest conditions across Ontario.

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