July 21 is generally a great time to visit Washington DC. While there is a slight chance of rain (24%), showers are usually brief. Expect comfortable 31°C weather. As it's peak season for Washington DC, we recommend booking your stay well in advance to secure the best rates.
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Essential Travel Info for Washington DC
Currency
USD
$ United States dollar
Language
English
Driving
Right side
Connect
The D.C. government operates a network o...
Safety
Moderate Safety
GPI: 2.44
Washington DC Weather Forecast for July 21
"Warm & Sunny. Expect average highs of 31.3°C. 24% chance of rain."
What to Wear in Washington DC in July
Based on historical data for July 21, Washington DC typically experiences temperatures between 21.6°C and 31.3°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 Washington DC
Smart Suitcase
- T-Shirt
- Light Clothing
Average High
31.3°C
Daytime Peak
Average Low
21.6°C
Nighttime Low
Feels Like
38.4°C
🔥 Heat index effect
Rain Chance
24%
Avg 2.1mm if it rains
Cloud Cover
55%
Overcast
Pressure
1014.5 hPa
Low volatility
Washington DC Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
~ Expect variable conditions. Have flexible plans and pack for multiple weather scenarios.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
05:00 - 10:00
16:00 - 19:00
Type I-II
🔴 15 min to burn
Type III-IV
🟡 23 min to burn
Type V-VI
🟢 38 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
25.2°C
Humid/Sticky
Heat Index
38.4°C
Feels hotter
😐 Best outdoor time:
Early morning (6-9 AM) or evening (after 6 PM)
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
~453
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Washington DC
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:00
☀️ Noon
12:15
🌇 Sunset
19:30
⏱️ Daylight
14h 29m
Wind Speed
12.7 km/h
Gentle breeze
Sunshine
11.5 hrs
Direct Sun (Cloud-free)
Humidity
70%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Washington DC
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 Washington DC
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, Washington DC on July 21 averages 31.3°C with a 24% precipitation probability. Wedding/Outdoor Event Score: 91/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Washington DC 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 (July 21) in other destinations
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📍 Is Washington DC Worth Visiting on July 21?
Planning a trip to Washington DC on July 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 31.3°C with a 24% historical precipitation risk.
✈️ Travel Logistics: Approximately 453 landing slots available daily during this period, indicating peak tourist activity.
📊 Historical Extremes: The hottest July 21 recorded in the last 30 years saw temperatures hit 37.5°C in 2019, while the coldest dropped to 18.4°C in 2018.