Geneva Weather in September

September in Geneva brings pleasant temperatures, with highs of 20°C (68°F) and nights dropping to 10°C (50°F). Rainfall is on the higher side this month, averaging around 123 mm (4.8 in), so keep a rain jacket handy.

Rainfall in Geneva in September

Looking at the last 30 years, the data shows about 12 days with rain, averaging 123 mm (4.8 in) for the month. Rainfall intensity is on the higher side this month. Expect more substantial showers rather than light, passing rain.

Temperature in Geneva in September

Geneva in September gets highs of 20°C (68°F) during the day and drops to 10°C (50°F) at night. This creates a mild day-to-night pattern that is generally easy to manage with the right clothing. With overnight lows of 10°C (50°F), nights are cold. The cold air does make for deep, comfortable sleep if you have enough blankets.

Sunshine in Geneva in September

With about 183 hours of sunshine, the area enjoys a nice balance of sun and overcast, creating a pleasant environment.

Average water temperature in September

At 20°C (68°F), the water is pleasant for swimming. Most people find this range ideal — cool enough to be refreshing, warm enough to stay in comfortably.

If you're inclined towards comfortable temperatures and drier conditions, September is a good time to visit Geneva.

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For a detailed overview over the year and the best time to visit Switzerland, check out our Geneva's climate page.

Geneva Temperature in September

Min Temperature 10°C (50°F)  

Max Temperature 20°C (68°F)  

Water Temperature 20°C (68°F)  

Chance of Rain 40%  

Precipitation 123 mm (4.8 in)  

Rainy days 12 days  

Humidity 74%  

Sunshine 183 hours  

Percentage Sunshine 55%  

Daily Historical Temperatures

50-year average (1976-2025)

Based on our historical records, temperatures in Geneva typically drop from around 23°C (73°F) at the start of September to approximately 18°C (64°F) by the end. Nights are cool, with lows typically ranging from 8°C (46°F) to 12°C (54°F).

Average temperatures in September

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Daily Historical Precipitation

50-year average (1976-2025)

Average daily rainfall for each day of the month based on long-term records.

Average precipitation in September

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Historical weather for Geneva in September

Browse day-by-day weather records for Geneva spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.

Historical weather Temperatures Precipitation

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Geneva historical weather extremes in September

According to our 49 years of weather records for Geneva, the following extremes were recorded between 1976 and 2025.

• Geneva recorded its highest September temperature of 31°C (88°F) on September 12, 2018.
• On September 17, 1988, Geneva saw its coldest September day with temperatures maxing out at 7°C (45°F).
• The coldest night in September in Geneva was on September 18, 1994, with a minimum of -2°C (28°F).
• The wettest day in September Geneva was on September 20, 2000 with 63 mm (2.5 in) of precipitation.

What to Wear in Geneva in September

Pleasant temperatures in September mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Prepare for significant rainfall with proper waterproof clothing and shoes. Expect water temperatures of around 20°C (68°F), which is ideal for taking a refreshing dip. Bring swimwear and consider packing a towel for drying off. Bring sunglasses since you'll have some sunny periods throughout the month

What To Do in Geneva in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

6/10

Cycling

9/10

Walking

9/10

Camping

3/10

Outdoor sports

9/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit Switzerland, check out our Geneva's climate page.

More climate data for Geneva

Temperature Rainfall Sunshine Humidity Water Temp

See the full Geneva climate overview or explore weather in Switzerland.