The best time to visit Basel is May, June and September, when average highs sit in the comfortable range and the light is generous over the Old Town — June reaches 24.5 °C with 11.8 hours of sunshine a day, while September eases to 21.6 °C with only 11 rain days. July and August are the warmest months but form the busy, higher-priced peak season, driven by school holidays. Winter is the quiet low season, cold and short on sun but calm for those who don't mind the chill.
Best months MayJuneSeptember
Basel month by month
Average highs and lows (°C), 2016–2025. Highlighted bars are the best months.
| Month | High | Low | Rain days | Sun / day |
|---|---|---|---|---|
| January | 6 °C | -0.6 °C | 15 | 4.4 h |
| February | 8.9 °C | 0.7 °C | 12 | 5.9 h |
| March | 12 °C | 2.3 °C | 13 | 7.9 h |
| April | 15.5 °C | 5.2 °C | 13 | 9.5 h |
| May | 19 °C | 9.3 °C | 15 | 10.3 h |
| June | 24.5 °C | 14.4 °C | 14 | 11.8 h |
| July | 26 °C | 15.7 °C | 13 | 12.3 h |
| August | 26.1 °C | 15.6 °C | 11 | 10.8 h |
| September | 21.6 °C | 11.9 °C | 11 | 9.3 h |
| October | 16.6 °C | 7.9 °C | 13 | 6.9 h |
| November | 9.7 °C | 2.9 °C | 15 | 4.9 h |
| December | 6.8 °C | 0.6 °C | 14 | 4.1 h |
How the months are picked.A month qualifies when its average high sits in the comfortable 20–28 °C band (scored down towards 9 °C and 37 °C), rain days are few and sunshine hours are high — at least 78 % of the city's best-scoring month. July and August are then set aside as peak season (school-holiday crowds and prices) whenever at least three other months qualify; where summer is the only comfortable window they stay. Figures are ten-year averages (2016-01-01 to 2025-12-31) from ERA5 reanalysis data via Open-Meteo (CC BY 4.0) for the city centre coordinates.
When to go, and what to expect
Spring (Mar–May)
Fresh and green — ideal for walkers and Old Town wandering.
Summer (Jun–Aug)
Warm and lively; June is the pick before crowds and prices rise.
Autumn (Sep–Nov)
September is a standout — mild, drier and uncrowded.
Winter (Dec–Feb)
For Christmas-market lovers and travellers happy in the cold.
Notable events
- February or March
- Basel Fasnacht (carnival)
- June
- Art Basel
- Late October–November
- Basel Autumn Fair (Herbstmesse)
- December
- Christmas Market
Frequently asked
Is Basel too hot in August?
Rarely — August highs average 26.1 °C, warm but comfortable, with 10.8 hours of sunshine a day. The bigger factor is crowds during the summer holiday peak.
What is the rainiest month?
January, May and November each record 15 rain days, the most of the year. May's rain comes with plenty of light, though, at 10.3 hours of sunshine a day.
Is winter worth visiting?
It's the quiet low season — January highs reach just 6 °C with only 4.4 hours of sunshine a day. Worthwhile for the December Christmas market and Fasnacht, but chilly and dim otherwise.
Know when to go? Now decide where to stay — our Basel area guide →
Areas of Basel
Best time to visit near here
Sources
- Open-Meteo historical weather API — monthly climate normals, 2016–2025 (CC BY 4.0)
- ERA5 reanalysis (ECMWF / Copernicus) — the underlying temperature, precipitation and sunshine data
- ReasonStay methodology — how the best months are computed and checked
An independent guide to Basel — honest, verified, no invented data. Climate figures: ERA5 via Open-Meteo, 2016–2025 averages; the best months are computed from them, not opinion.