Environment Canada has issued a special weather statement for Windsor-Essex and Chatham-Kent because of a warm and humid airmass is settling into southern Ontario.
The forecaster says while heat warning criteria is not expected to be reached in most places, this is the first very warm and humid weather of the season.
These conditions pose a health risk when you are not used to the heat.
Everyone is a risk from heat, especially older adults, infants and young children, and people with chronic illnesses. You are advised to drink plenty of cool liquids before feeling thirsty, and keep cool by dressing for the weather and spending a few hours each day in a cool place.
Maximum temperatures will range from 28 C to 30 C across the regions Friday and from 29 C to 32 C Saturday. Overnight lows will range from 17 C to 20 C tonight and from 18 C to 21 C Saturday night.
Maximum temperatures Sunday and Monday are forecast to be in the high twenties with overnight lows in the mid-to-high teens.
