Muggy airmass sets stage for multi-day storm risk in Ontario
A risk for thunderstorms will bloom over southern Ontario each of the next three days
A muggy airmass draped over southern Ontario heading into this weekend will set the stage for a multi-day risk for strong to severe thunderstorms across the region.
We’ll see the potential for storms to build each day Friday, Saturday, and Sunday. Some of the storms could turn severe with strong winds and heavy rainfall.
Make sure you keep an eye on the radar—especially if you have outdoor plans—and stay aware of any severe weather watches or warnings issued in your area.
DON'T MISS: What’s the wettest month in your corner of Canada?
Multi-day storm risk for southern Ontario
The workweek will end with some thunderstorm energy moving into southwestern Ontario on Friday.
Dynamics are favourable for some of these storms to potentially grow stronger close to the Michigan border near Windsor and Sarnia. Strong wind gusts and heavy rainfall will be the main threats from these storms, and there’s a chance for some small hail, as well.
Thunderstorms could form as far east as London and into the western end of the Greater Toronto Area (GTA), but they should remain on the weaker side as we head through the day.
MUST SEE: The Weather Network's exclusive summer 2025 forecast
The risk will continue on Saturday and Sunday as the soupy air provides plenty of energy for storms to fire up.
Saturday’s storm threat will evolve across southwestern Ontario along the shorelines of Lake Huron, as well as the northern and eastern shores of Georgian Bay. These storms will track inland through the night and weaken as they approach the GTA through the overnight hours.
Sunday’s potential for active weather will see thunderstorms develop inland and track through the GTA toward eastern Ontario.
Storms on Saturday and Sunday could reach severe limits. Be sure to check back through the weekend for the latest.