Temperatures in September
It's pleasantly warm in September in Sion with an average temperature of 22°C. Temperatures this month range from a low of 19°C to a high of 25°C. At night, you can expect temperatures between 8°C and 14°C.
Max and Min Temperatures per Day
This chart shows the daily maximum and minimum temperatures in degrees Celsius for Sion in September. The red line indicates the max temperatures, and the blue line shows the minimums.
Start of September
The month of September starts in Sion with warm temperatures, averaging around 24°C during the day and nights close to 13°C. There’s little chance of precipitation. The weather is mostly sunny and dry.
Mid-September
By mid-September, the average daytime temperature drops to around 23°C, with nights close to 13°C. Not much precipitation expected during this period. It’s mostly dry with sunshine.
End of September
By the end of September, the average daytime temperature in Sion will be around 20°C, with nights close to 10°C. Barely any chance of precipitation. The weather will mostly be dry with lots of sunshine.
Precipitation in September
In September, there is an average of 27 mm of precipitation, spread over 6 days. The wind speed is around 4 Bft, mostly coming from the Southwest.
The average precipitation chance is 21% per day this month. Though that seems low, there are also a few days with a higher chance of precipitation.
Precipitation Chance
This chart shows the daily precipitation chance (in percentages) in September for Sion. 0% means it never rained on that day in the past 10 years, and 100% means it rained every day. All values in between represent the average chance of precipitation on that day.
Sion in September |
London | ||
|---|---|---|---|
 Average Temperature |
22°C | 20°C | |
 High Temp |
25°C | 22°C | |
| Low Temp |
19°C | 17°C | |
 Total Precipitation |
27 mm | 44 mm | |
| Rainy Days |
6 days | 8 days | |
August
UV index
The UV index is a maximum of 8 this month. That's a very high value on the intensity scale of 1 to 11. Unprotected skin can burn within 10-15 minutes.
Is September a good time to visit Sion?
Want nice weather? Then September is a great time to be in Sion. You’ll have pleasant temperatures and not too much rain this month.
Temperature records for Sion in September
With 35°C, Sion hit the highest temperature in the last 10 years in September 2023. The lowest daytime temperature in this month was 9°C in 2022. The extreme night temperatures ranged from a low of 2°C to a high of 19°C.
Check out the climate of Sion for all months and discover the best travel time
Curious about the climate in other parts of Switzerland? Check out the weather and climate in places like Zurich, Geneva, Valais, or have a look at other destinations in Switzerland.
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Daily Temperature in September in Sion
This chart shows the average daily temperatures, both day and night, for each day in September in Sion, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in September in Sion
The chart below shows the average daily precipitation in September for Sion, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for September, you can expect around 6 days of rain in Sion.
Daily UV Index in September in Sion
This chart shows the average daily UV index in September in Sion, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in September in Sion Over the Years
This chart shows the average temperature in September in Sion, measured in degrees Celsius, over the past years.
Total Precipitation in September in Sion Over the Years
This chart shows the average precipitation in September in Sion, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Daily climate in September for Sion
Click on a specific day in September for detailed info on the typical weather on that day in Sion. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in September in Sion
Have you been to Sion in September?
Share your weather experience in September in Sion.
Average Weather in Sion by Month
Click on a month below to see detailed weather info for Sion. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
