May 21 is generally a great time to visit Basel. While there is a slight chance of rain (38%), showers are usually brief. Expect comfortable 20°C weather. Take advantage of the off-peak calm in Basel to see the sights without the usual crowds.
View the full calendar
Essential Travel Info for Basel
Currency
CHF
Fr. Swiss franc
Language
French
+3 more
Driving
Right side
Connect
As of Sept 2021, Basel has 4G from Salt,...
Safety
Very High Safety
GPI: 1.357
Basel Weather Forecast for May 21
"Mild & Comfortable. Expect average highs of 19.8°C. 38% chance of rain."
What to Wear in Basel in May
Based on historical data for May 21, Basel typically experiences temperatures between 9.8°C and 19.8°C. We recommend packing light jacket, long pants, umbrella to stay comfortable. With a 38% chance of rain, keeping a raincoat or umbrella handy is a smart move.
Complete Packing Guide
Weekly breakdown & essential items for Basel
Smart Suitcase
- Light Jacket
- Long Pants
- Umbrella
Average High
19.8°C
Daytime Peak
Average Low
9.8°C
Nighttime Low
Feels Like
19.8°C
🌤️ Feels accurate
Rain Chance
38%
Avg 3mm if it rains
Cloud Cover
65%
Light drizzle
Pressure
1016 hPa
Medium volatility
Basel Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 84% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
04:00 - 10:00
16:00 - 20:00
Type I-II
🔴 19 min to burn
Type III-IV
🟡 29 min to burn
Type V-VI
🟢 48 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
15°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 Switzerland
Flight Traffic
Quiet
22/100 pressure index
Health Advisory
Required
1 vaccine • View Details →
Landing Slots
~39
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Basel
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
04:47
☀️ Noon
12:27
🌇 Sunset
20:08
⏱️ Daylight
15h 20m
Wind Speed
12.4 km/h
Gentle breeze
Sunshine
10.7 hrs
Direct Sun (Cloud-free)
Humidity
74%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Basel
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 Basel
Travel Comfort Index
Real-time tourism conditions
Weather Quality
⛅ Good
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, Basel on May 21 averages 19.8°C with a 38% precipitation probability. Wedding/Outdoor Event Score: 89/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Basel Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
May 28
20.7°C • 32% rain
Score
94
May 25
20.2°C • 34% rain
Score
93
May 26
20.3°C • 34% rain
Score
93
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (May 21) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Basel Worth Visiting on May 21?
Planning a trip to Basel on May 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 19.8°C with a 38% historical precipitation risk.
✈️ Travel Logistics: Approximately 39 landing slots available daily during this period, indicating manageable crowd levels.
💉 Health Advisory: 7 vaccinations are recommended for Switzerland, including COVID-19.
📊 Historical Extremes: The hottest May 21 recorded in the last 30 years saw temperatures hit 24.6°C in 2020, while the coldest dropped to 6.5°C in 2017.