Montreal's weather is about to feel hotter than 45 °C and this is when the heat will peak

The first weekend of summer is upon us, Montreal — and the weather isn't wasting any time.

A heat wave is barreling toward the city, and while daytime highs will climb into the low 30s, what'll really make you sweat is the humidex, which could push the "feels like" temperature into the mid-40s.

According to The Weather Network's latest forecast for the city, Friday and Saturday will see milder weather, with highs in the mid-20s (feels like 28–32 °C). But things heat up fast from Sunday onward:

Montreal's weather over the next few days

• Sunday, June 22: High around 30 °C, but humidity will push the “feels like” temperature to 40 °C—plan for a hot and sticky day, with a chance of late afternoon storms.
• Monday, June 23: Daytime high hits 34 °C, but it's the humidex that steals the show, spiking to 46 °C — the hottest point of the stretch. Expect a typical summer thunderstorm risk by evening.
• Tuesday, June 24 (Saint‑Jean-Baptiste Day): Temps stay scorching at 33 °C, with a humidex of 44 °C. Another round of humidity-fueled discomfort, with some thunderstorm potential late day. Overnight lows will hover between 22–25 °C, but with sticky humidity, it'll feel like 35 °C.

Health risks and tips

Such extreme heat increases the risk of heat-related illnesses like heat exhaustion and heat stroke, which can come on quickly. As per Health Canada, seniors, young children, people with chronic illnesses, and those working outdoors are especially at risk.

During extreme heat, Health Canada suggests doing the following:

• Stay hydrated: Drink regularly (even if you're not feeling thirsty) and keep a water bottle with you.
• Take it easy outside: Avoid strenuous activity between 11 a.m.– 3 p.m., and take frequent breaks in the shade.
• Dress smart: opt for loose, light-coloured clothes, sunglasses, and a wide-brimmed hat.
• Find AC or shade: Spend time in air-conditioned or shady spots, like shopping centres, libraries, or public pools.
• Know the signs: Watch for dizziness, nausea, confusion, and fainting. These are red flags of heat exhaustion or heat stroke.
• Prepare your home: Close blinds during the day, open windows at night if cooler, and run a fan or A/C if available.

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