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Live forecasts update automatically; written guidance last reviewed 16 June 2026 by the Canada Perspective Weather Desk. Data from Environment and Climate Change Canada and other national met services via Open-Meteo.
Live data from Open-Meteo · updates automatically ·
The live forecast above shows today’s conditions for Mont-Saint-Hilaire, a town in the Richelieu Valley east of Montreal where the mountain’s 411-metre peak often creates its own microclimate of cooler air and higher precipitation compared to the surrounding plain.
What does the mountain do to local weather?
Mont Saint-Hilaire forces moist air from the St. Lawrence and Richelieu rivers to lift and cool, increasing cloud cover and rainfall on the windward slopes. The lee side, just a few kilometres away, tends to be drier and sunnier. This effect is most noticeable during spring and fall frontal passages.
How does this compare to weather Montreal?
Because the mountain sits only 40 kilometres east of downtown, weather Montreal and Mont-Saint-Hilaire share the same large-scale patterns—humid summers, cold snowy winters—but the peak can be 2–4°C cooler and receive 10–20% more annual precipitation. Valley frost is also common earlier in autumn.
How does Mont-Saint-Hilaire’s elevation affect snowfall?
The mountain receives more snow than the valley because colder temperatures keep precipitation frozen longer. Lake-effect and river-effect snows also enhance amounts on the north-facing slopes during winter nor’easters.
Why is the area prone to fog?
Nighttime radiative cooling in the Richelieu Valley, combined with moist air from the river and the mountain’s forest canopy, frequently produces valley fog that can linger until midday, especially after rain or snowmelt.
What is the best time for clear skies?
Late August through October offers the highest chance of stable high-pressure systems, giving sunny days and cool nights. The mountain’s foliage season also draws many visitors who enjoy the crisp, dry weather.
Sources
For conditions across Canada, visit our Canada weather hub. If severe storms or alerts are issued, check the weather warning page for the Mont-Saint-Hilaire region. Environment Canada mont saint-hilaire forecasts are updated regularly and remain the most reliable source for this area.