August 21 is statistically one of the best days of the year in Denver. With minimal rain risk (13%) and pleasant highs of 30°C, it's ideal for outdoor adventures. 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 August 21
"Warm & Sunny. Expect average highs of 29.7°C. 13% chance of rain."
What to Wear in Denver in August
Based on historical data for August 21, Denver typically experiences temperatures between 14.8°C and 29.7°C. We recommend packing t-shirt, light clothing, layers (onion system) to stay comfortable. Trends suggest it will stay mostly dry (13% 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
29.7°C
Daytime Peak
Average Low
14.8°C
Nighttime Low
Feels Like
30.3°C
🔥 Feels accurate
Rain Chance
13%
Avg 0.5mm if it rains
Cloud Cover
42%
Overcast
Pressure
1013.7 hPa
Low volatility
Denver Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
✓ This date historically delivers consistent weather 79% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
05:00 - 10:00
16:00 - 18:00
Type I-II
🔴 14 min to burn
Type III-IV
🟡 21 min to burn
Type V-VI
🟢 35 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
17.5°C
Noticeable
Heat Index
30.3°C
Feels hotter
🙂 Best outdoor time:
Any time during daylight hours
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in United States
Flight Traffic
High
100/100 pressure index
Health Advisory
Healthy
Routine only • View Details →
Landing Slots
~1,160
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Denver
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:19
☀️ Noon
12:04
🌇 Sunset
18:50
⏱️ Daylight
13h 30m
Wind Speed
13.9 km/h
Gentle breeze
Sunshine
11.4 hrs
Direct Sun (Cloud-free)
Humidity
48%
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
🔴 Very Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Stable conditions. Low risk of headaches.
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 August 21 averages 29.7°C with a 13% 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 (August 21) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Denver Worth Visiting on August 21?
Planning a trip to Denver on August 21? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year typically offers vibrant summer conditions averaging 29.7°C with a 13% historical precipitation risk.
✈️ Travel Logistics: Approximately 1,160 landing slots available daily during this period, indicating peak tourist activity.
📊 Historical Extremes: The hottest August 21 recorded in the last 30 years saw temperatures hit 37.3°C in 2023, while the coldest dropped to 11.9°C in 2016.