Avg High
Montreal in August
Avg Low
Rain
Daylight
14h
What to expect
August in Montreal is late summer, with a settled seasonal pattern already in place. The month is warm and inviting for long walks, with a noticeable cool-down after sunset. There is plenty of daylight to stretch outdoor time. Most days feel close to what the averages suggest, with straightforward pacing.
August in context
How it compares to the rest of the year in Montreal.
Hottest (avg)
#2 / 12
Wettest (avg)
#4 / 12
Daylight Hours
#4 / 12
Windiest (avg)
#12 / 12
Highest UV
#4 / 12
Most Humid
#7 / 12
Monthly climate breakdown
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight hours
- 14.1 h
- UV index (max)
- 7
- Typical sun hours
- 04:56 - 18:59
Rain & Snow
- Total rain
-
- Rainy days
- 14 days
- Cloud cover (avg)
- 54%
Humidity & Wind
- Humidity (avg)
- 73%
- Wind (avg)
-
- Wind (max gusts)
-
Daily climate explorer
Day 15 selected for August. Typical high 23.8°C and low 16.1°C.
Typical disruptions in August
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in August.
Rain High impact
Rain disruption Measures: Likely rain disruption days. Observed about 19% of days (5.9 days/month) in August. Historical risk signal only, not a day-by-day forecast.
5.9 days / month
~19% of days
Why this matters
- Expected days 5.9 days / month
- Probability ~19% of days
- Intensity Up to ~38mm (P95)
Rain disruption risk appears on ~6 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Washout risk Measures: Washout day risk. Observed about 17% of days (5.4 days/month) in August. Historical risk signal only, not a day-by-day forecast.
5.4 days / month
~17% of days
Why this matters
- Expected days 5.4 days / month
- Probability ~17% of days
- Intensity Up to ~40mm (P95)
Washout conditions are possible on ~5 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 10% of days (3.2 days/month) in August. Historical risk signal only, not a day-by-day forecast.
3.2 days / month
~10% of days
Why this matters
- Expected days 3.2 days / month
- Probability ~10% of days
- Intensity Up to ~47mm (P95)
Heavy rain is possible on ~3 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Wind High impact
Stormy conditions Measures: Storm-impact proxy days. Observed about 3% of days (0.8 days/month) in August. Historical risk signal only, not a day-by-day forecast.
0.8 days / month
~3% of days
Why this matters
- Expected days 0.8 days / month
- Probability ~3% of days
- Intensity Up to ~67km/h (P95)
Stormy conditions are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Wind High impact
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 2% of days (0.5 days/month) in August. Historical risk signal only, not a day-by-day forecast.
0.5 days / month
~2% of days
Why this matters
- Expected days 0.5 days / month
- Probability ~2% of days
- Intensity Up to ~74km/h (P95)
Strong gusts are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Heat Moderate
Hot feels-like days Measures: Hot feels-like days (>=32C). Observed about 2% of days (0.8 days/month) in August. Historical risk signal only, not a day-by-day forecast.
0.8 days / month
~2% of days
Why this matters
- Expected days 0.8 days / month
- Probability ~2% of days
- Intensity Up to ~35°C (P95)
Feels-like heat >=32C is possible on ~1 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Show all disruptions (20 more)
Rain High impact
Washout run Measures: Multi-day washout runs. Observed about 1.0 days/month in August. Historical risk signal only, not a day-by-day forecast.
1.0 days / month
Probability unavailable
Why this matters
- Expected days 1.0 days / month
- Probability —
- Intensity Up to ~25mm (P95)
Multi-day washout runs are possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Very heavy rain Measures: Very heavy rain days (>=25mm). Observed about 2% of days (0.5 days/month) in August. Historical risk signal only, not a day-by-day forecast.
0.5 days / month
~2% of days
Why this matters
- Expected days 0.5 days / month
- Probability ~2% of days
- Intensity Up to ~103mm (P95)
Very heavy rain is possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Extreme rain Measures: Extreme rain days (>=50mm). Observed about 1% of days (0.2 days/month) in August. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~117mm (P95)
Extreme rain is possible on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Humidity Moderate
Muggy days Measures: Muggy days (dew point >=20C). Observed about 2% of days (0.6 days/month) in August. Historical risk signal only, not a day-by-day forecast.
0.6 days / month
~2% of days
Why this matters
- Expected days 0.6 days / month
- Probability ~2% of days
- Intensity Up to ~21°C (P95)
Muggy conditions are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rain Minor
Wet days Measures: Wet days (>=0.1mm). Observed about 58% of days (17.9 days/month) in August. Historical risk signal only, not a day-by-day forecast.
17.9 days / month
~58% of days
Why this matters
- Expected days 17.9 days / month
- Probability ~58% of days
- Intensity Up to ~21mm (P95)
Measurable rain is possible on ~18 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloud Minor
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 43% of days (13.4 days/month) in August. Historical risk signal only, not a day-by-day forecast.
13.4 days / month
~43% of days
Why this matters
- Expected days 13.4 days / month
- Probability ~43% of days
- Intensity Up to ~99% (P95)
Cloudy skies are possible on ~13 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rain Minor
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 41% of days (12.7 days/month) in August. Historical risk signal only, not a day-by-day forecast.
12.7 days / month
~41% of days
Why this matters
- Expected days 12.7 days / month
- Probability ~41% of days
- Intensity Up to ~18h (P95)
Several rainy hours are possible on ~13 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Wind Minor
Gusty days Measures: Gusty days (>=40 km/h). Observed about 29% of days (9.1 days/month) in August. Historical risk signal only, not a day-by-day forecast.
9.1 days / month
~29% of days
Why this matters
- Expected days 9.1 days / month
- Probability ~29% of days
- Intensity Up to ~62km/h (P95)
Gusty conditions are possible on ~9 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Rain Minor
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 27% of days (8.4 days/month) in August. Historical risk signal only, not a day-by-day forecast.
8.4 days / month
~27% of days
Why this matters
- Expected days 8.4 days / month
- Probability ~27% of days
- Intensity Up to ~19h (P95)
Wet-most-of-day conditions are possible on ~8 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Humidity Minor
High humidity Measures: High humidity days (RH >=80%). Observed about 25% of days (7.8 days/month) in August. Historical risk signal only, not a day-by-day forecast.
7.8 days / month
~25% of days
Why this matters
- Expected days 7.8 days / month
- Probability ~25% of days
- Intensity Up to ~92% (P95)
High humidity is possible on ~8 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Cloud Minor
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 21% of days (6.6 days/month) in August. Historical risk signal only, not a day-by-day forecast.
6.6 days / month
~21% of days
Why this matters
- Expected days 6.6 days / month
- Probability ~21% of days
- Intensity Up to ~100% (P95)
Mostly cloudy skies are possible on ~7 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Humidity Minor
Humid days Measures: Humid days (dew point >=18C). Observed about 12% of days (3.6 days/month) in August. Historical risk signal only, not a day-by-day forecast.
3.6 days / month
~12% of days
Why this matters
- Expected days 3.6 days / month
- Probability ~12% of days
- Intensity Up to ~21°C (P95)
Humid conditions are possible on ~4 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Cloud Minor
Overcast days Measures: Overcast days (cloud cover >=95%). Observed about 7% of days (2.3 days/month) in August. Historical risk signal only, not a day-by-day forecast.
2.3 days / month
~7% of days
Why this matters
- Expected days 2.3 days / month
- Probability ~7% of days
- Intensity Up to ~100% (P95)
Overcast skies are possible on ~2 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Humidity Minor
Convective risk Measures: Convective storm risk proxy. Observed about 4% of days (1.3 days/month) in August. Historical risk signal only, not a day-by-day forecast.
1.3 days / month
~4% of days
Why this matters
- Expected days 1.3 days / month
- Probability ~4% of days
- Intensity Up to ~21°C (P95)
Convective risk signal appears on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Heat Minor
Hot days Measures: Hot days (>=30C). Observed about 2% of days (0.6 days/month) in August. Historical risk signal only, not a day-by-day forecast.
0.6 days / month
~2% of days
Why this matters
- Expected days 0.6 days / month
- Probability ~2% of days
- Intensity Up to ~32°C (P95)
Hot days are possible on ~1 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Visibility Minor
Fog-likely signal Measures: Fog-likely visibility proxy. Observed about 2% of days (0.5 days/month) in August. Historical risk signal only, not a day-by-day forecast.
0.5 days / month
~2% of days
Why this matters
- Expected days 0.5 days / month
- Probability ~2% of days
- Intensity Up to ~95% (P95)
Fog-likely conditions are possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Other Minor
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data Measures: Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data. Observed about 2% of days (0.5 days/month) in August. Historical risk signal only, not a day-by-day forecast.
0.5 days / month
~2% of days
Why this matters
- Expected days 0.5 days / month
- Probability ~2% of days
- Intensity Up to ~95 (P95)
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data is possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Heat Minor
Warm nights Measures: Warm nights (min >=22C). Observed about 1% of days (0.2 days/month) in August. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~23°C (P95)
Warm nights are possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Heat Minor
Heatwave run Measures: Heatwave runs (>=3 hot days). Observed about 0.1 days/month in August. Historical risk signal only, not a day-by-day forecast.
0.1 days / month
Probability unavailable
Why this matters
- Expected days 0.1 days / month
- Probability —
- Intensity Up to ~31°C (P95)
Heatwave runs are possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat Minor
Feels-like heatwave Measures: Feels-like heatwave runs (>=3 days). Observed about 0.1 days/month in August. Historical risk signal only, not a day-by-day forecast.
0.1 days / month
Probability unavailable
Why this matters
- Expected days 0.1 days / month
- Probability —
- Intensity Up to ~32°C (P95)
Feels-like heatwave runs are possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Frequently asked questions
Is August a good time to visit Montreal?
Typical August days in Montreal reach highs of 23°C (73°F) with nights around 15°C (59°F). It usually feels warm by day and mild after dark. Overall, August sits in the middle of the Montreal climate range.
What are temperatures like in August?
Daytime temperatures in August typically peak near 23°C (73°F), while nights drop to around 15°C (59°F). Expect warm afternoons and mild evenings.
How much does it rain in August?
Rainfall in August averages 101 mm (4.0 in) across roughly 14 days. Overall it is a very wet time of year, so a light rain jacket and waterproof shoes are very handy.
How many hours of daylight are there in August?
You can expect about 14 hours of daylight in August. Sunrise is typically around 04:56 and sunset near 18:59. You get long days with comfortable amounts of daylight.
How strong is the sun in August?
UV levels are often high (around 7). Regular sunscreen and a hat are recommended.
Is it windy in August?
In August, average wind speeds are around 10 km/h (6 mph), with gusts on the windiest days reaching about 50 km/h (31 mph). On the ground, it is it often feels breezy, especially in more exposed spots or along the coast.