August 18 is generally a great time to visit Montreal. While there is a slight chance of rain (24%), showers are usually brief. Expect comfortable 25°C weather. Expect a bustling atmosphere in Montreal right now—this is when the city truly comes alive with visitors. Note: August 18 is Discovery Day in Montreal, so expect special events, closures, and festive atmosphere.
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Essential Travel Info for Montreal
Currency
CAD
$ Canadian dollar
Language
English
+1 more
Driving
Right side
Connect
Montreal has four area codes: the long-s...
Safety
Very High Safety
GPI: 1.389
Montreal Weather Forecast for August 18
"Mild & Comfortable. Expect average highs of 24.8°C. 24% chance of rain."
What to Wear in Montreal in August
Based on historical data for August 18, Montreal typically experiences temperatures between 16.5°C and 24.8°C. We recommend packing t-shirt, light clothing to stay comfortable. Trends suggest it will stay mostly dry (24% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for Montreal
Smart Suitcase
- T-Shirt
- Light Clothing
Average High
24.8°C
Daytime Peak
Average Low
16.5°C
Nighttime Low
Feels Like
25.6°C
☀️ Feels accurate
Rain Chance
24%
Avg 1.5mm if it rains
Cloud Cover
53%
Overcast
Pressure
1014.8 hPa
Medium volatility
Montreal Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
✓ Weather is generally predictable, but pack for minor variations. A light backup layer is recommended.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
04:00 - 09:30
16:00 - 18:00
Type I-II
🔴 20 min to burn
Type III-IV
🟡 30 min to burn
Type V-VI
🟢 50 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
19.6°C
Noticeable
Heat Stress
Low
No heat warning
😊 Best outdoor time:
Any time during daylight hours
Travel & Logistics Insights
Local Calendar
Holiday
Discovery Day
Flight Traffic
High
90/100 pressure index
Health Advisory
Required
1 vaccine • View Details →
Landing Slots
~307
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Montreal
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
04:59
☀️ Noon
11:59
🌇 Sunset
18:59
⏱️ Daylight
13h 59m
Wind Speed
15 km/h
Gentle breeze
Sunshine
10.7 hrs
Direct Sun (Cloud-free)
Humidity
73%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Montreal
Smart Flight Estimator
Airport-to-Airport Logistics
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Travel Health & Safety in Montreal
Travel Comfort Index
Real-time tourism conditions
Weather Quality
☀️ Excellent
Tourist Crowds
🔴 Very Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Moderate fluctuations. Some sensitivity possible.
Weather unlikely to affect joint pain.
Moderate fish activity expected.
Air quality is acceptable. Sensitive individuals should limit prolonged outdoor exertion.
Regional Safety Profile
Seismic Activity
Rare minor tremors. Buildings are earthquake-resistant.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, Montreal on August 18 averages 24.8°C with a 24% precipitation probability. Wedding/Outdoor Event Score: 97/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Montreal Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (August 18) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Montreal Worth Visiting on August 18?
Planning a trip to Montreal on August 18? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year is characterized by pleasant mild weather averaging 24.8°C with a 24% historical precipitation risk.
🎉 Local Event: The date coincides with Discovery Day, which may influence local business hours and event availability.
✈️ Travel Logistics: Approximately 307 landing slots available daily during this period, indicating manageable crowd levels.
💉 Health Advisory: 6 vaccinations are recommended for Canada, including COVID-19.
📊 Historical Extremes: The hottest August 18 recorded in the last 30 years saw temperatures hit 27.5°C in 2021, while the coldest dropped to 11.4°C in 2025.