Sunday, June 20th 2021, 3:40 pm - June 20 officially marks the start of summer, but those living on the eastern Prairies and northwestern Ontario will get a rude awakening, but luckily the chill will be short-lived.
Summer officially arrived Sunday, but depending on where you live on the Prairies and in Ontario, it may not feel like it. A deep upper trough will send temperatures plummeting, lingering into early next week for some, ahead of the arrival of the searing heat from the southwestern U.S., though not nearly as extreme. The start of the season will be accompanied by un-summer-like temperatures on the eastern Prairies, with daytime highs sitting in the low-to-mid teens. The temperature plunge will be accompanied by frost risk Sunday night as overnight lows dip into the single digits. The cooler air will hang on into Monday, too, before a surge of heat returns to the region for Tuesday. A closer look, below.
Visit our Complete Guide to Summer 2021 for an in-depth look at the Summer Forecast, tips to plan for it and much more!
SUNDAY/MONDAY: CHILLY AIR WELCOMES IN SUMMER, RISK OF FROST FOR SOME
An extraordinary shot of rather chilly weather is on the way for Sunday and Monday across parts of the eastern Prairies with daytime highs struggling to reach the low or mid-teens in many locales, which also means there will be a risk of frost in the overnight period.
The cooler air will also spill into northwestern Ontario, where temperatures will reach the upper teens. Alberta will be somewhat warmer, with daytime highs approaching, hitting or exceeding the 20-degree mark in some places.
On the plus side, conditions will be fair across most of the Prairies, with a mix of sun and cloud for most, though southern Manitoba may see a stray passing shower.
Overnight lows will dip into the single digits across the region, elevating the risk for widespread frost. The cooler than usual temperatures will linger into Monday.
LOOK AHEAD: TEMPERATURES REBOUND NEXT WEEK, BUT WILL COOL OFF AGAIN
Fortunately, the frost threat and cool temperatures will be short-lived on the Prairies and northwestern Ontario, as sizzling summer heat will push its way north into the region from the southwestern U.S. on Tuesday.
Temperatures will quickly rebound with hot weather for Alberta Monday, hitting the mid-to-upper 20s in Edmonton and Calgary, and approaching the 30s in extreme southern areas. Tuesday will be even warmer, with the warmth spreading east.
The quick shot of heat continues to push east across the region for the middle of next week, followed by a shot of cooler weather -- especially for Saskatchewan and Manitoba, late week.
There will also be the potential for showers and thunderstorms along and ahead of the cold front. Meanwhile, very warm weather will return to Alberta for the weekend.
Stay tuned to The Weather Network for the latest forecast updates across the Prairies.