Climate averages 1991–2020
Basel weather
in May.
A mild, wet month: the 5th warmest and the wettest of the year.
Long-term climate patterns, not a forecast for a particular trip.
May is a mild month in Basel: daytime highs average 18.7°C and nights cool to about 8.9°C. By daytime temperature it is the 5th warmest of the 12 months.
Expect about 129 mm of rain on roughly 17 days, which makes May a wet month (the wettest month of the year). Daylight, from sunrise to sunset, lasts about 15 h 06 min on an average May day.
The nearest other city in this atlas is Mulhouse (28 km away). In May its highs average 18.4°C, about as warm as Basel, with 93 mm of rain.
Among the 8 cities listed in Switzerland, Basel ranks 1st of 8 for the warmest May highs and 4th of 8 for the driest May (rainfall, lowest first). The mean May high of those 8 cities is 17.5°C; Basel is 1.3°C warmer than that mean.
From May to June, average highs rise by 3.6°C to 22.3°C, and monthly rainfall falls from 129 mm to 118 mm.
The annual picture
May in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Basel climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 5.4°C-1.7°C | -1.7°C | 80 | 13.5 | 8.99 h |
| February | 6.9°C-1.5°C | -1.5°C | 73 | 11.7 | 10.210 h |
| March | 11.1°C1.4°C | 1.4°C | 83 | 13.5 | 11.912 h |
| April | 15.0°C4.6°C | 4.6°C | 90 | 14.1 | 13.614 h |
| May, selected | 18.7°C8.9°C | 8.9°C | 129 | 16.8 | 15.115 h |
| June | 22.3°C12.7°C | 12.7°C | 118 | 15.8 | 15.916 h |
| July | 24.5°C14.8°C | 14.8°C | 121 | 15.4 | 15.616 h |
| August | 24.5°C14.9°C | 14.9°C | 125 | 15.1 | 14.314 h |
| September | 20.1°C10.8°C | 10.8°C | 95 | 12.6 | 12.613 h |
| October | 15.4°C6.7°C | 6.7°C | 97 | 13.2 | 10.911 h |
| November | 9.4°C2.1°C | 2.1°C | 94 | 13.0 | 9.49 h |
| December | 5.8°C-0.8°C | -0.8°C | 101 | 14.1 | 8.59 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
May in nearby cities
- Mulhouse in MayFrance · 28 kmHigh 18.4°C · Low 9.2°C · 93 mm rain
- Freiburg in MayGermany · 53 kmHigh 18.9°C · Low 9.9°C · 105 mm rain
- Bern in MaySwitzerland · 69 kmHigh 16.3°C · Low 7.0°C · 117 mm rain
- Zürich in MaySwitzerland · 76 kmHigh 17.9°C · Low 8.6°C · 144 mm rain
- Luzern in MaySwitzerland · 79 kmHigh 17.9°C · Low 8.1°C · 188 mm rain
- Winterthur in MaySwitzerland · 87 kmHigh 17.6°C · Low 8.5°C · 119 mm rain
- Villingen-Schwenningen in MayGermany · 89 kmHigh 15.9°C · Low 7.1°C · 133 mm rain
- Strasbourg in MayFrance · 115 kmHigh 19.0°C · Low 9.6°C · 83 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Basel) is explained once on the Basel year overview and on the Sources, method and limits page.