Heat and Humidity Begins Sunday
- Austin Gagnier
- Jul 26, 2025
- 1 min read
Another period of hot and humid weather will begin for Southern Ontario on Sunday. Temperatures in the 30s with humidex values in the 40s are expected across the region by Monday. There will be little relief at night, with temperatures remaining in the 20s with remaining humidity.

For Sunday, the most humid conditions are expected to be in urban areas, including Windsor and Toronto. Humidex values will be between 40 and 45ºC, likely on the lower end of this range. Much of the region will see Humidex values between 35 and 40ºC, with areas along the Lake Huron shoreline seeing Humidex values between 30 to 35ºC.
Heat Warnings have been issued by Environment Canada as of Saturday evening.


More humid conditions are expected for Monday, with the entire region expected to see Humidex values of 40 to 45ºC.
This heat event may continue into Wednesday for some areas. Further forecasts will be posted in the coming days.
Extreme Heat affects everyone. Ensure you stay hydrated even before you feel thirsty, check on young children, the elderly, and your pets.












