The best months to visit Interlaken are June, July, August and September, when average highs sit comfortably between 20.4 °C and 24.5 °C and the mountains stay open for hiking and cable-car days. September is especially pleasant, with a 20.4 °C average high, 15 rain days and 9.3 hours of sunshine a day. July and August are peak season, coinciding with European school holidays, so trails, trains and the town centre are at their busiest. Winter is the quiet low season for Interlaken itself, with January highs of just 6.4 °C, though the surrounding ski slopes draw their own crowds.
Best months JuneJulyAugustSeptember
Interlaken month by month
Average highs and lows (°C), 2016–2025. Highlighted bars are the best months.
| Month | High | Low | Rain days | Sun / day |
|---|---|---|---|---|
| January | 6.4 °C | 0.8 °C | 17 | 5.6 h |
| February | 8.9 °C | 2.1 °C | 13 | 6.9 h |
| March | 11.3 °C | 3 °C | 15 | 8.1 h |
| April | 14.6 °C | 5.5 °C | 15 | 9.9 h |
| May | 17.6 °C | 8.9 °C | 21 | 9.8 h |
| June | 23.1 °C | 13.8 °C | 17 | 11.7 h |
| July | 24.3 °C | 15.8 °C | 18 | 12.2 h |
| August | 24.5 °C | 16 °C | 16 | 10.9 h |
| September | 20.4 °C | 13.4 °C | 15 | 9.3 h |
| October | 17.1 °C | 9.8 °C | 13 | 7.7 h |
| November | 10.7 °C | 5.1 °C | 14 | 5.8 h |
| December | 8.3 °C | 2.6 °C | 14 | 5.3 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)
Good for green valleys and fewer people, though high trails may still hold snow.
Summer (Jun–Aug)
Prime time for the Jungfrau region and lakes — book early if you come in peak.
Autumn (Sep–Nov)
September is a sweet spot — warm, clear and calmer than midsummer.
Winter (Dec–Feb)
For skiers and snow-lovers heading to the slopes, not for lakeside sightseeing.
Notable events
- Summer
- Unspunnen-related folk and alphorn traditions / summer open-air events
- August (1 August)
- Swiss National Day celebrations with fireworks over the lakes
- September
- Jungfrau Marathon from Interlaken to Kleine Scheidegg
- December
- Christmas markets and Advent season
Frequently asked
Is Interlaken too hot in August?
No. August highs average 24.5 °C with lows around 16 °C, comfortable for hiking, though it is the busiest month alongside July.
What is the rainiest month?
May sees the most wet days, with 21 rain days, followed by July with 18. Summer still delivers plenty of sun — July has 12.2 hours of sunshine a day.
Is winter worth it?
For skiing, yes — but Interlaken town is cold and quiet, with January highs of just 6.4 °C and only 5.6 hours of sunshine a day. For sightseeing, June to September is far better.
Know when to go? Now decide where to stay — our Interlaken area guide →
Areas of Interlaken
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 Interlaken — honest, verified, no invented data. Climate figures: ERA5 via Open-Meteo, 2016–2025 averages; the best months are computed from them, not opinion.