Switzerland Geneva Weather in September — Climate Guide
September in Geneva is high
September is high for Geneva.
September in Geneva is a top month — averaging about 21°C/12°C, holding warm, pleasant days as the summer crowds thin, making it one of the best weather-to-value windows of the year.
The Jet d'Eau still runs, lakeside dining and perch are still in season, and the lakefront stays inviting with milder, less-packed conditions than midsummer. It's ideal for the city sights and all the day trips, with the bonus of the Lavaux grape harvest getting under way among the terraced vineyards near Lausanne.
Travel score
Geneva September Weather Stats
Avg High
21°C
Avg Low
12°C
Rainy Days
9
75mm total
Sunshine
6h
Daily avg
Humidity
72%
comfortable
UV Index
5
Moderate
Wind
9 km/h
Gusts 22
Crowds
Busy
At attractions
September Sunrise & Sunset
Air Quality
PM2.5
17 μg/m³
PM10
31 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
21°C
Nighttime
12°C
Humidity and wind affect how the actual temperature feels.
Wind
9 km/h
Max gust 22 km/h
Activities Recommended for September
September Travel Pros & Cons
Pros
- Warm days with thinning crowds
- Excellent weather-to-value balance
- Lavaux grape harvest begins
- Lakeside dining still in season
Cons
- Cooler evenings
- More showers late month
- Still fairly high prices early on
- Shorter days than summer
September Events & Festivals
- Lavaux grape harvest beginning
- Pleasant warm days with thinning crowds
- Lakeside dining still in season
- Excellent shoulder-season weather
Geneva in September — Full Picture
September in Geneva is a top month — averaging about 21°C/12°C, holding warm, pleasant days as the summer crowds thin, making it one of the best weather-to-value windows of the year.
The Jet d'Eau still runs, lakeside dining and perch are still in season, and the lakefront stays inviting with milder, less-packed conditions than midsummer. It's ideal for the city sights and all the day trips, with the bonus of the Lavaux grape harvest getting under way among the terraced vineyards near Lausanne.
Early September keeps a summer feel; by late month it cools toward autumn with crisper air and the first turning leaves. Prices ease a little from the peak, and popular spots are easier to get into.
Note: evenings cool noticeably, and showers become a bit more frequent later in the month, so pack a light jacket and a waterproof.
What to Wear & What to Pack
Warm early autumn — around 21°C/12°C, comfortable by day with cooler evenings. Light layers, a light jacket for evenings, sunglasses, and SPF. A packable waterproof for showers later in the month.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
15°C
6.3°C
11/mo
Summer (Jun·Jul·Aug)
24.7°C
14.3°C
9.7/mo
Autumn (Sep·Oct·Nov)
Current15°C
7.7°C
10/mo
Winter (Dec·Jan·Feb)
5°C
0.3°C
10.7/mo
Geneva Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| 4° | 0° | 11d·76mm | 2h | 82% | 1 | Quiet | Shoulder | |
| 6° | 0° | 10d·64mm | 3.5h | 78% | 2 | Quiet | Shoulder | |
| 11° | 3° | 10d·65mm | 4.5h | 72% | 3 | Quiet | Shoulder | |
| 15° | 6° | 11d·68mm | 5.5h | 70% | 5 | Moderate | Shoulder | |
| May (Best) | 19° | 10° | 12d·80mm | 6.5h | 70% | 6 | Busy | Peak |
| June (Best) | 23° | 13° | 11d·75mm | 7.5h | 67% | 7 | Busy | Peak |
| July (Best) | 26° | 15° | 9d·73mm | 8h | 64% | 8 | Very busy | Peak |
| August (Best) | 25° | 15° | 9d·80mm | 7.5h | 67% | 7 | Very busy | Peak |
| September (Best) | 21° | 12° | 9d·75mm | 6h | 72% | 5 | Busy | Peak |
| 15° | 8° | 10d·86mm | 4h | 78% | 3 | Moderate | Shoulder | |
| 9° | 3° | 11d·82mm | 2.5h | 82% | 1 | Quiet | Shoulder | |
| 5° | 1° | 11d·81mm | 2h | 84% | 1 | Moderate | Peak |
View Other Months
Geneva September Hotel Picks
Frequently Asked Questions
Is September a good time to visit Geneva?
Geneva in September is high. Tourist crowds are busy and flight/hotel prices are peak.
What's the average temperature in Geneva in September?
Geneva September averages a high of 21°C and a low of 12°C.
Does it rain much in Geneva in September?
Geneva September averages 75mm of rainfall over about 9 rainy days.
What should I wear in Geneva in September?
Warm early autumn — around 21°C/12°C, comfortable by day with cooler evenings. Light layers, a light jacket for evenings, sunglasses, and SPF. A packable waterproof for showers later in the month.
What time are sunrise and sunset in Geneva in September?
Geneva September sunrise is 07:10 and sunset is 19:45, with 12h 35min of daylight.
What's the air quality like in Geneva in September?
Geneva September air quality (AQI) averages 45, rated Good. PM2.5 averages 17μg/m³.
What activities are recommended in Geneva in September?
In September, Geneva is great for Lakefront + Jet d'Eau + Old Town, Lausanne + Lavaux harvest, Mont Blanc / Annecy day trips.
Is September peak season in Geneva?
Geneva September crowds are busy and prices are peak. Advance reservations are strongly recommended.
Best Months to Visit Geneva
View Other Months
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.