Switzerland Interlaken Weather in September — Climate Guide
September in Interlaken is very-high
Interlaken Weather in September — Quick Answer
As of 2026- Avg temp
- 20° / 10°
- Rainfall
- 100mm · 11 days
- Crowds
- Busy
As of 2026, Interlaken in September averages a high of 20°C and low of 10°C with 100mm of rain over about 11 days. Cool autumn. Light coat + sweater.
September is very-high for Interlaken.
BEST MONTH after July — fewer crowds + autumn foliage + still all mountains operating + Jungfraujoch perfect visibility.
Travel score
Interlaken September Weather Stats
Avg High
20°C
Avg Low
10°C
Rainy Days
11
100mm total
Sunshine
6h
Daily avg
Humidity
78%
moderate
UV Index
6
High
Wind
8 km/h
Gusts 20
Sea Temp
15°C
lake swimming chilly
Crowds
Busy
At attractions
September Sunrise & Sunset
Air Quality
PM2.5
10 μg/m³
PM10
18 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
20°C
Nighttime
10°C
Humidity and wind affect how the actual temperature feels.
Wind
8 km/h
Max gust 20 km/h
Activities Recommended for September
September Travel Pros & Cons
Pros
- 20°C ideal
- Autumn foliage
- Reduced crowds
- All mountains operating
- Best visibility
Cons
- Hotels still elevated
- Daylight dropping
September Events & Festivals
- Autumn foliage starts mid-September
Interlaken in September — Full Picture
BEST MONTH after July — fewer crowds + autumn foliage + still all mountains operating + Jungfraujoch perfect visibility.
What to Wear & What to Pack
Cool autumn. Light coat + sweater.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
14°C
4.3°C
12.7/mo
Summer (Jun·Jul·Aug)
23.7°C
12°C
13/mo
Autumn (Sep·Oct·Nov)
Current13.7°C
5°C
11/mo
Winter (Dec·Jan·Feb)
4°C
-2.3°C
9.7/mo
Interlaken Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| 3° | -3° | 10d·75mm | 3h | 80% | 1 | Busy | Peak | |
| 5° | -2° | 9d·65mm | 4h | 78% | 2 | Busy | Peak | |
| 10° | 1° | 11d·80mm | 5h | 75% | 3 | Moderate | Shoulder | |
| 14° | 4° | 13d·100mm | 6h | 73% | 5 | Quiet | Low season | |
| 18° | 8° | 14d·130mm | 7h | 70% | 6 | Moderate | Shoulder | |
| June (Best) | 22° | 11° | 14d·140mm | 7h | 72% | 8 | Busy | Peak |
| July (Best) | 25° | 13° | 12d·130mm | 8h | 72% | 9 | Very busy | Peak |
| August (Best) | 24° | 12° | 13d·130mm | 7h | 75% | 8 | Very busy | Peak |
| September (Best) | 20° | 10° | 11d·100mm | 6h | 78% | 6 | Busy | Peak |
| 14° | 5° | 10d·85mm | 5h | 80% | 4 | Moderate | Shoulder | |
| 7° | 0° | 12d·100mm | 3h | 80% | 2 | Quiet | Low season | |
| 4° | -2° | 10d·75mm | 3h | 80% | 1 | Busy | Peak |
View Other Months
Interlaken September Hotel Picks
Frequently Asked Questions
Is September a good time to visit Interlaken?
Interlaken in September is very-high. Tourist crowds are busy and flight/hotel prices are peak.
What's the average temperature in Interlaken in September?
Interlaken September averages a high of 20°C and a low of 10°C.
Does it rain much in Interlaken in September?
Interlaken September averages 100mm of rainfall over about 11 rainy days.
What should I wear in Interlaken in September?
Cool autumn. Light coat + sweater.
What time are sunrise and sunset in Interlaken in September?
Interlaken September sunrise is 06:55 and sunset is 19:55, with 13h of daylight.
What's the air quality like in Interlaken in September?
Interlaken September air quality (AQI) averages 30, rated Good. PM2.5 averages 10μg/m³.
What activities are recommended in Interlaken in September?
In September, Interlaken is great for Jungfraujoch (perfect visibility), Lauterbrunnen, Grindelwald.
Is September peak season in Interlaken?
Interlaken September crowds are busy and prices are peak. Advance reservations are strongly recommended.
Best Months to Visit Interlaken
View Other Months
Planning a September trip to Interlaken?
You've checked the weather — next come the budget and the route.
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.