Extreme heat to start the week in parts of Simcoe Muskoka

Hot, sticky weather returns Alessandra Carneiro has more on the hot, sticky weather and how to protect yourself from the heat.

Barrie, Ont. — A heat warning is in effect for parts of Simcoe Muskoka Monday.

Environment Canada issued the warning for:

Innisfil

New Tecumseth

Angus

Orangeville

Grand Valley

Southern Dufferin County

Shelburne

Mansfield

Northern Dufferin County

Environment Canada said the heat and humidity could extend into the middle of the week.

Daytime temperatures are expected to be between 30-32 degrees, with humidex values between 37-40.

Nighttime temperatures are not expected to drop below 21 degrees.

A heat warning is issued when the forecast has two or more consecutive days with maximum daytime temperatures of 31 degrees or warmer, together with nighttime minimum temperatures of 20 degrees or warmer.

A heat warning can also be issued when there is a forecast of two or more consecutive days with humidex values expected to reach 40 degrees or higher.

The humidity continues for a second week. Forecasted humidex values Friday were expected to top 38 degrees across Simcoe Muskoka.

Average temperatures for this time of year are 24 degrees.

People are advised to watch for the effects of heat illness, drink plenty of water, stay in a cool place.

The heat and humidity can also affect the air quality and prompt the Air Quality Health Index to reach the high-risk category.