Montreal's steamiest day of the summer expected Wednesday

The most oppressive day of the summer so far is expected on Wednesday as humidex values climb to 40 in many parts of Southwestern Quebec.

Environment and Climate Change Canada have issued heat warnings because of the oppressive humidity.

The agency is warning people to limit physical activity because of the risk of heat-related illnesses such as heat stroke and heat exhaustion. And people are being encouraged to stay in a cool place and to drink plenty of water even before feeling thirsty.

The actual temperature in Montreal is expected to climb to 31 degrees Celsius on Wednesday, which is not a record for July 20. (The record high for July 20 is 33.3 C set in 1991.)

Temperatures will also remain elevated on Wednesday night. Montreal is expecting an overnight low of 24 C. (The normal high for this time in July is 27 C and the normal low is 16 C.)

Daytime highs will drop back into the upper 20s on Thursday with humidex values in the upper 30s as a cold front brings showers and a risk for thunderstorms. Behind that cold front, humidity will begin to drop into the weekend however real relief from the humidity won’t come until Monday.

So far this summer Montreal has only experienced one official heat wave with three consecutive days of 30 C or above. That heat wave occurred early in the season from May 12 to May 14. Humidex values during that stretch of hot weather were in the mid 30s.

Heat warnings have been issued for these areas on Wednesday. Plan your outdoor activities accordingly.

— ECCC Weather Quebec (@ECCCWeatherQC) July 19, 2022