Montreal Weather in August
In August, Montreal averages a high of 25°C (78°F) and a low of 17°C (62°F), from 55 years of daily records (1971–2026).
25°C
Average high
78°F
17°C
Average low
62°F
36°C
Record high
96°F · August 1, 1975
6°C
Record low
43°F · August 22, 1993
What August Is Like in Montreal
- The August heat record, 36°C (96°F) on August 1, 1975, has stood for 51 years.
- The coldest August reading, 6°C (43°F) on August 22, 1993, has not been matched in 33 years.
- August in Montreal has become 1.0°C (1.8°F) warmer on average: the 2012–2026 average against 1970–1989.
- A typical August brings 2.8 days above 30°C (86°F).
At least 1 mm of rain falls on 32% of August days, and the month averages 101 mm in total.
Warmest: 2021 (28.8°C)Latest: 2026 (25.2°C)10-year averageLong-run average (25.3°C)
Look Up a Day in August
See the weather in Montreal on any August date, year by year.
Source: NOAA GHCN-Daily, Mctavish (1994–2026); Montreal Mcgill (1971–1993); Montreal/St-Hubert A (1979–2009). Averages cover 1971–2026. How we compute this