Friday, September 18, 2026, will bring a daytime high of 20°C to Montreal, Quebec, according to the latest forecast. The temperature is expected to rise to that level under a moderate UV index of 5, while winds remain light throughout the day.
As the day progresses, the light wind conditions are projected to persist, limiting any significant gusts or shifts in temperature. The moderate UV rating suggests that sun exposure will be noticeable but not extreme, prompting typical precautions for outdoor activities.
When night falls, temperatures are forecast to drop to around 8°C, marking a cooler overnight period after the mild daytime warmth. The temperature swing from day to night reflects the seasonal transition that Montreal is currently experiencing.
The forecast arrives as summer draws to an end in the region. Over the coming days, weather patterns are expected to remain relatively stable, offering a series of days with similar mild temperatures and moderate sun levels. Residents can anticipate a continuation of these conditions, which are characteristic of the late‑summer period in the area.
Overall, the weather outlook for Friday presents a balance of comfortable daytime warmth, manageable UV exposure, and a cooler night, aligning with the broader trend of pleasant weather as the season shifts toward autumn.