September 15 is generally a great time to visit Ottawa. While there is a slight chance of rain (25%), showers are usually brief. Expect comfortable 21°C weather. As it's peak season for Ottawa, we recommend booking your stay well in advance to secure the best rates.
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Essential Travel Info for Ottawa
Currency
CAD
$ Canadian dollar
Language
English
+1 more
Driving
Right side
Connect
The area codes for Ottawa are613and the ...
Safety
Very High Safety
GPI: 1.389
Ottawa Weather Forecast for September 15
"Mild & Comfortable. Expect average highs of 21.2°C. 25% chance of rain."
What to Wear in Ottawa in September
Based on historical data for September 15, Ottawa typically experiences temperatures between 12.4°C and 21.2°C. We recommend packing light jacket, long pants to stay comfortable. Trends suggest it will stay mostly dry (25% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for Ottawa
Smart Suitcase
- Light Jacket
- Long Pants
Average High
21.2°C
Daytime Peak
Average Low
12.4°C
Nighttime Low
Feels Like
21.4°C
☀️ Feels accurate
Rain Chance
25%
Avg 1.9mm if it rains
Cloud Cover
55%
Overcast
Pressure
1018.1 hPa
Medium volatility
Ottawa Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 83% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 15 for extended outdoor time
Type I-II
🔴 31 min to burn
Type III-IV
🟡 47 min to burn
Type V-VI
🟢 78 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
16.8°C
Noticeable
Heat Stress
Low
No heat warning
😊 Best outdoor time:
Any time during daylight hours
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in Canada
Flight Traffic
High
99/100 pressure index
Health Advisory
Required
1 vaccine • View Details →
Landing Slots
~175
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Ottawa
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:42
☀️ Noon
11:59
🌇 Sunset
18:16
⏱️ Daylight
12h 33m
Wind Speed
14 km/h
Gentle breeze
Sunshine
9.1 hrs
Direct Sun (Cloud-free)
Humidity
76%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Ottawa
Smart Flight Estimator
Airport-to-Airport Logistics
unlock smart flight estimates
Add your home location in settings to see airport details.
Travel Health & Safety in Ottawa
Travel Comfort Index
Real-time tourism conditions
Weather Quality
☀️ Excellent
Tourist Crowds
🟡 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, Ottawa on September 15 averages 21.2°C with a 25% precipitation probability. Wedding/Outdoor Event Score: 97/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Ottawa Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
September 17
20.7°C • 19% rain
Score
99
September 18
20.6°C • 18% rain
Score
99
September 19
20.8°C • 18% rain
Score
99
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (September 15) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Ottawa Worth Visiting on September 15?
Planning a trip to Ottawa on September 15? 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 21.2°C with a 25% historical precipitation risk.
✈️ Travel Logistics: Approximately 175 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 September 15 recorded in the last 30 years saw temperatures hit 27.9°C in 2018, while the coldest dropped to 6.6°C in 2020.