Hot and humid conditions expected to continue through Thursday.
Daytime maximum temperatures: 30 to 33 degrees Celsius, with humidex values 38 to 42.
Nighttime minimum temperatures: 19 to 21 degrees Celsius.
Hot and humid air can also bring deteriorating air quality and can cause the Air Quality Health Index to approach the high risk category.
Extreme heat affects everyone.
The risks are greater for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors.
Watch for the effects of heat illness: swelling, rash, cramps, fainting, heat exhaustion, heat stroke and the worsening of some health conditions.
Never leave people or pets inside a parked vehicle.
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@canada.ca or tweet reports using #ONStorm.