The province has been gripped by an intense heat wave since Sunday.
On Tuesday, temperatures in Montreal hit 35.1°C, edging past the previous record of 35.0°C set on June 30, 1964.
On Monday, Dorval saw a high of 34.9°C, while Gatineau reached a scorching 36.6°C, breaking the 1988 record.
While the heat wave is expected to subside, the summer 2025 weather forecast says there will be more intense humidity and heat in the future.
What is the hottest it's ever been in Montreal?
The warmest day ever in Montreal occurred during the historic heatwave of 1975, with a temperature of 37.6C (99.6F) on August 1, 1975.
How to cool off in a heat wave?
According to their website, the City of Montreal suggests taking the following precautions during a heat wave in order to reduce health risks:
Drink lots of water before you feel thirsty
Spend a few hours a day in an air-conditioned or cool location
Take a cool shower or bath or cool your skin with a damp cloth
Reduce your physical efforts
Wear light-couloured clothing
Don't drink alcoholic beverages, beverages with a high caffeine content or high sugary content in moderation, as they dehydrate you
The opening hours of many public places could be extended during a heat wave, so be sure to look up the site’s opening hours before you make your way there.
Find an indoor or outdoor facility near you: neighbourhood parks, nature parks and large parks; swimming pools, wading pools, beaches, mist stations and play fountains; libraries and air-conditioned places
If you don’t have access to air conditioning close to home, or if you have difficulty getting around, here are a few tips for your home:
Avoid using heat-generating appliances (stove, oven, dryer, TV, lights, etc.)
Close windows, curtains, blinds and doors during the day. Air your home out in the evening, at night or early in the morning
Circulate air with portable or ceiling fans
Use the technique of placing a frozen water bottle in front of a fan to diffuse cooler air
During a heat wave, your health could degrade rapidly. Call Info-Santé at 811 or talk to a health care professional if you have these symptoms:
Exhaustion (fatigue)
Dehydration (dry mouth)
Redness or rash on the skin
Headaches
Dizziness (lightheadedness)
Confusion
If you have these symptoms and are also feverish, you may be experiencing heat stroke. This is a medical emergency. Call 911 to get help quickly.
The following people are at higher during a heat wave:
People who are 65 or older
People living with chronic, cardiovascular, respiratory, kidney or neurological conditions or diabetes
People living with mental health conditions or with alcohol or drug addiction
People who work outdoors or near a heat source
Children younger than 4 years old
During a heat wave, take a few minutes, on a regular basis, to look out for the well-being of your loved ones and the people in your neighbourhood who are more isolated
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