September 15 is generally a great time to visit Denver. While there is a slight chance of rain (15%), showers are usually brief. Expect comfortable 26°C weather. As it's peak season for Denver, we recommend booking your stay well in advance to secure the best rates.
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Essential Travel Info for Denver
Currency
USD
$ United States dollar
Language
English
Driving
Right side
Safety
Moderate Safety
GPI: 2.44
Denver Weather Forecast for September 15
"Warm & Sunny. Expect average highs of 26°C. 15% chance of rain."
What to Wear in Denver in September
Based on historical data for September 15, Denver typically experiences temperatures between 10.3°C and 26°C. We recommend packing t-shirt, light clothing, layers (onion system) to stay comfortable. Trends suggest it will stay mostly dry (15% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for Denver
Smart Suitcase
- T-Shirt
- Light Clothing
- Layers (Onion System)
Average High
26°C
Daytime Peak
Average Low
10.3°C
Nighttime Low
Feels Like
26.3°C
☀️ Feels accurate
Rain Chance
15%
Avg 0.6mm if it rains
Cloud Cover
34%
Overcast
Pressure
1013.2 hPa
Medium volatility
Denver 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
05:00 - 10:00
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
14.4°C
Pleasant
Heat Stress
Low
No heat warning
😊 Best outdoor time:
Any time during daylight hours
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in United States
Flight Traffic
High
96/100 pressure index
Health Advisory
Healthy
Routine only • View Details →
Landing Slots
~1,109
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Denver
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:42
☀️ Noon
11:56
🌇 Sunset
18:10
⏱️ Daylight
12h 28m
Wind Speed
13.4 km/h
Gentle breeze
Sunshine
10.9 hrs
Direct Sun (Cloud-free)
Humidity
49%
Comfortable
Travel Intelligence
Exclusive flight analytics & health data for Denver
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 Denver
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 excellent. Perfect for outdoor activities.
Regional Safety Profile
Seismic Activity
Zero seismic activity detected in 30 years.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, Denver on September 15 averages 26°C with a 15% precipitation probability. Wedding/Outdoor Event Score: 100/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Denver Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Compare Other Cities
Same date (September 15) in other destinations
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📍 Is Denver Worth Visiting on September 15?
Planning a trip to Denver on September 15? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year typically offers vibrant summer conditions averaging 26°C with a 15% historical precipitation risk.
✈️ Travel Logistics: Approximately 1,109 landing slots available daily during this period, indicating peak tourist activity.
📊 Historical Extremes: The hottest September 15 recorded in the last 30 years saw temperatures hit 33.8°C in 2018, while the coldest dropped to 7.9°C in 2016.