October 21 is statistically one of the best days of the year in Denver. With minimal rain risk (12%) and pleasant highs of 18°C, it's ideal for outdoor adventures. Expect a bustling atmosphere in Denver right now—this is when the city truly comes alive with visitors.
View the full calendar
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 October 21
"Mild & Comfortable. Expect average highs of 18.4°C. 12% chance of snow."
What to Wear in Denver in October
Based on historical data for October 21, Denver typically experiences temperatures between 2.7°C and 18.4°C. We recommend packing light jacket, long pants, layers (onion system) to stay comfortable. Trends suggest it will stay mostly dry (12% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for Denver
Smart Suitcase
- Light Jacket
- Long Pants
- Layers (Onion System)
Average High
18.4°C
Daytime Peak
Average Low
2.7°C
Nighttime Low
Feels Like
18.4°C
🌤️ Feels accurate
Snow Chance
12%
Avg 0.5mm if it snows
Snowfall
0.2 cm
~12% chance
Pressure
1014.4 hPa
Medium volatility
Denver Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
✓ This date historically delivers consistent weather 76% 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
🔴 40 min to burn
Type III-IV
🟡 60 min to burn
Type V-VI
🟢 100 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
7.5°C
Dry air
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
85/100 pressure index
Health Advisory
Healthy
Routine only • View Details →
Landing Slots
~985
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Denver
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
06:17
☀️ Noon
11:45
🌇 Sunset
17:13
⏱️ Daylight
10h 56m
Wind Speed
13.1 km/h
Gentle breeze
Sunshine
9.0 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
💰💰 Moderate
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 October 21 averages 18.4°C with a 12% precipitation probability. Wedding/Outdoor Event Score: 91/100."
— 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
Better Alternatives Nearby
Consider these dates within ±7 days
October 16
19.1°C • 7% rain
Score
93
October 17
19.2°C • 5% rain
Score
93
October 18
19.3°C • 7% rain
Score
93
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (October 21) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Denver Worth Visiting on October 21?
Planning a trip to Denver on October 21? 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 18.4°C with a 12% historical precipitation risk.
✈️ Travel Logistics: Approximately 985 landing slots available daily during this period, indicating peak tourist activity.
📊 Historical Extremes: The hottest October 21 recorded in the last 30 years saw temperatures hit 25.2°C in 2023, while the coldest dropped to -0.6°C in 2019.