Sion weather in May
Temperature, rain and sunshine in May: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in May
Good
Best time to visit: May – October
What is the weather like in Sion in May?
In May, Sion is mild: daytime highs average 18 °C, and nights cool down to about 8 °C. The sun shines for around 7 hours a day. It rains often – on about 19 days, adding up to 167 mm. All in all, May is a good month for a holiday in Sion.
May compared
How the weather changes from April to June. Tap a month to open it.
More details for May
- Daylight
- 14 h 56 min05:59 – 20:55
- UV index
- 8 · very highclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 9 km/haverage daily peakAll months
- Cloud cover
- 67 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Snow days
- 1 day1 cm or more of fresh snowAll months
- Time zone
- UTC+2Europe/Zurich
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %73 %
- Few rainy daysweight 30 %0 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Mountain air”.
What to pack in May
- Sunscreen
- Sunglasses & sun hat
- A jumper for the evenings
- Rain jacket or umbrella
Sion in May: quick answers
Is Sion hot in May?
No. In May, Sion is mild: daytime highs average 18 °C and nights drop to about 8 °C.
Does it rain much in Sion in May?
It rains often – on about 19 days, adding up to 167 mm.
Sion month by month
The whole year in SionAll destinations: SwitzerlandWhere to go in May
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences