Montréal weather in August
In August, Montréal has an average high of 25 °C77 °F and an average low of 15 °C59 °F, with about 97 mm3.8 in of precipitation. It is the 2nd warmest month of the year and ranks 4th for precipitation.
How August compares with other months
Compared with July, August is 0.6 °C1.1 °F cooler on average. Compared with September, August is 4.2 °C7.6 °F warmer on average and wetter by 10 mm0.4 in. Daylight lasts about 14.1 hours around the middle of the month. Average relative humidity is 74% and the average cloud amount 57%.
Is August a good time to visit Montréal?
Yes — August is one of the most comfortable months to visit Montréal by our comfort score, which favours average highs of 21–28 °C, lows above 5 °C, little rain and moderate humidity.
What to wear in August
For Montréal in August, pack light summer clothes such as T-shirts, shorts or light dresses, an extra layer for the cooler mornings and evenings and an umbrella or light rain jacket.
August in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Montréal | 2577 | 1559 | 973.8 |
| Trois-Rivières | 2476 | 1458 | 983.9 |
| Sherbrooke | 2475 | 1457 | 1194.7 |
| Ottawa | 2578 | 1558 | 883.5 |
| Québec | 2374 | 1558 | 1084.3 |
| Kingston | 2476 | 1966 | 793.1 |
| Albany | 2882 | 1762 | 1194.7 |
| Manchester | 2781 | 1661 | 953.7 |
| Syracuse | 2882 | 1762 | 1014.0 |
Nearby places that are more than 1 °C1.8 °F warmer in August: Kingston, Albany, Manchester and Syracuse; cooler: Sherbrooke.
Other months in Montréal
- January−7 °C19 °F / −18 °C0 °F
- February−5 °C23 °F / −16 °C3 °F
- March0 °C33 °F / −9 °C15 °F
- April9 °C49 °F / −1 °C31 °F
- May17 °C63 °F / 7 °C44 °F
- June22 °C72 °F / 13 °C55 °F
- July25 °C78 °F / 16 °C60 °F
- August25 °C77 °F / 15 °C59 °F
- September21 °C70 °F / 10 °C50 °F
- October12 °C54 °F / 3 °C38 °F
- November4 °C39 °F / −4 °C26 °F
- December−4 °C26 °F / −12 °C10 °F
Frequently asked questions
How warm is Montréal in August?
In August the average high in Montréal is 25 °C (77 °F) and the average low is 15 °C (59 °F).
Does it rain a lot in Montréal in August?
On average about 97 mm (3.8 in) of precipitation falls in August; it ranks 4th of the 12 months.
Is August the warmest month in Montréal?
No. The warmest month in Montréal is July, with an average high of 25 °C (78 °F). The coldest month is January, with an average low of -18 °C (0 °F).
How long is the day in Montréal in August?
In the middle of August the day in Montréal lasts about 14.1 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Montréal in August?
The average relative humidity in August is about 74%. Combined with warm days, it can feel muggy.
How cloudy is Montréal in August?
On average about 57% of the sky is covered by cloud in August. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 38 m, while Montréal lies at about 216 m. Temperatures on this page were therefore adjusted by −1.2 °C2.1 °F using the standard lapse rate of 6.5 °C per 1,000 m.