Monday, August 23rd 2021, 9:52 pm - Heat warnings will remain in effect for much of southern and eastern Ontario through the middle of the week.
The hot and humid pattern gripping Ontario this week isn’t going anywhere anytime soon. Heat warnings are in effect for much of southern and eastern Ontario through midweek. We could see scattered thunderstorms for the next few days, with downpours posing the main threat. More on what to expect throughout the week ahead, below.
TUESDAY: TROPICAL MOISTURE KEEPS HUMIDITY UP, FEEDS STORM CHANCES
A heat warning stretches from southwestern Ontario through southern Quebec through Wednesday.
High temperatures in the lower 30s will be common across southern Ontario during the day on Tuesday. Humidex values will climb into the mid- to upper-30s in most locations and push 40 for some.
Tropical moisture blankets much of Eastern Canada this week as southerly winds pump in humid air from the States and the remnants of Henri make their way toward the Maritimes.
Scattered thunderstorms are possible during the day on Tuesday. The best chance for pop-up storms exists in southwestern Ontario. These storms should remain below severe limits, but tropical downpours are possible as storms wring out the deep moisture in the atmosphere.
Farther to the west, a storm system will track through northwestern Ontario on Tuesday, bringing some measurable precipitation to regions still dealing with dry conditions and wildfires. The additional precipitation will help further improve the fire situation here.
WEDNESDAY AND BEYOND: MORE RAIN IN NORTH, HOT, MUGGY WEATHER TO LINGER IN SOUTH
Conditions will remain hot and humid through the middle of this week. A cold front will bring a bit of relief across the region toward the end of the week, but the reprieve will be brief.
Somewhat cooler weather is expected at the end of the week or the weekend, but the heat and humidity will return on the weekend, though temperatures won't be quite as warm as in recent days.
The final days of August and into early September should be near seasonal or on the warm side of seasonal.
Stay with The Weather Network for the latest forecast across Ontario.