Siviez Weather in September

September in Siviez typically sees daytime highs of 14°C (57°F) and nighttime lows of 3°C (37°F). Rainfall is also possible this month, so it's worth packing an umbrella.

Rainfall in Siviez in September

Records from the past 30 years suggest around 14 days of rain, with 120 mm (4.7 in) average for the month. When it rains this month, it tends to come down fairly heavily. Showers can be substantial even if they don't last all day.

Temperature in Siviez in September

Siviez in September gets highs of 14°C (57°F) during the day and drops to 3°C (37°F) at night. Temperatures can feel cooler in the morning and evening, so layering is often the best approach. Nights fall to 3°C (37°F), which is cold enough to feel it indoors too. A good thick duvet makes all the difference for a comfortable night's sleep.

Sunshine in Siviez in September

Enjoy a sunny month with about 210 hours of sunshine, making it one of the brighter months of the year despite the cool conditions.

Wind Speed in Siviez in September

Wind speeds average 2 m/s (4 knots) during September. At this speed, expect light breezes that you can feel on your face and cause leaves to rustle gently. Since this is an average, some days are calmer with barely any wind while others have more noticeable gentle breezes.

If your ideal day consists of dry skies and pleasant temperatures, July and August typically offer the best circumstances for Siviez.

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

Siviez Temperature in September

Min Temperature 3°C (37°F)  

Max Temperature 14°C (57°F)  

Chance of Rain 47%  

Precipitation 120 mm (4.7 in)  

Rainy days 14 days  

Humidity 71% *  

Windspeed 2 m/s (4 knots) *  

Sunshine 210 hours *  

Percentage Sunshine 65% *  

* Data from: Sion, Switzerland (9 KM, 5 Miles).

Daily Historical Temperatures

50-year average (1976-2025)

Based on our historical records, temperatures in Siviez typically drop from around 21°C (70°F) at the start of September to approximately 18°C (64°F) by the end. Nights are cool, with lows typically ranging from 7°C (45°F) to 10°C (50°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 Siviez in September

Browse day-by-day weather records for Siviez 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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‹ January February March April May June July August September October November December ›

Siviez historical weather extremes in September

Based on 49 years of weather observations (1976-2025), these are the most extreme conditions recorded in Siviez.

• Siviez recorded its highest September temperature of 34°C (93°F) on September 5, 2023.
• The lowest daytime temperature in September was 7°C (45°F), recorded on September 26, 2020.
• The coldest night in September in Siviez was on September 29, 1995, with a minimum of -12°C (10°F).
• The wettest September day on record brought 35 mm (1.4 in) of precipitation to Siviez (September 13, 1997).

What to Wear in Siviez in September

The weather can swing between comfortable and chilly in September, so flexibility is key. Pack a variety of tops, at least one warm layer, and both shorts and long pants. This gives you options no matter what the day brings. Expect heavy rainfall, so bring good rain protection and waterproof bags. You'll definitely want to pack sunglasses and sunscreen. There will be plenty of bright sunshine this month.

What To Do in Siviez in September

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

Swimming

4/10

Cycling

5/10

Walking

5/10

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 Siviez's climate page.

More climate data for Siviez

Temperature Rainfall Sunshine Humidity Wind Speed

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