Montreal weather in August
August in Montreal: warm, rainy, with very humid — an excellent time to visit.
#3 of 12 months in Montreal · #196 of 604 destinations to visit in August · comfort 85/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Montreal climate normals — August
| Daytime high | 24°C / 75°F | 🌤 warm |
|---|---|---|
| Nighttime low | 16°C / 61°F | |
| Feels like (high) | 24°C / 75°F | |
| Rainfall | 126 mm / 5 in | 🌧 rainy |
| Rainy days | 14 days | |
| Humidity | 77% | 💦 very humid |
| Dew point | 15°C / 58°F | |
| Sunshine | 10.5 h/day | |
| Daylight | 14.1 h | |
| Wind | 16 km/h / 10 mph | |
| Air quality (US AQI) | 51 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Montreal in August — FAQ
- Is August a good time to visit Montreal?
- August in Montreal: warm, rainy, with very humid — an excellent time to visit. It ranks #3 of 12 months for Montreal on SeasonMap's comfort score (85/100).
- What is the weather like in Montreal in August?
- In August, Montreal averages a daily high of 24°C and a low of 16.2°C, with about 125.8 mm of rain over roughly 14 rainy days.
- What is the air quality in Montreal in August?
- Montreal has a mean US Air Quality Index of about 51 in August.