Environment Canada issued weather statements for parts of southernwestern Ontario on Monday, warning residents to brace for the “first heat event of the season”.
“A warm and humid air mass has moved over Southern Ontario today,” the agency said.
“The daytime maximum temperatures are likely to reach the low 30s with overnight lows near 20 degrees Celsius.”
Given the humidity the temperature could feel more like 40 C during the day, the agency said.
These high temperatures can pose a health risk to people not used to the heat, especially older adults, infants and young children and people with chronic illnesses, Environment Canada warned.
The weather statements affect portions of Southwestern Ontario and the Golden Horseshoe Area.
Temperatures will be lower on Tuesday with daytime highs expected to remain below 30 degrees.