Annual mean 6°C · wettest around May · prevailing wind S
Warmest
17.9 °C
Coldest
-2.6 °C
Wettest
26%
Windiest
3.7 m/s
Prevailing
S
3.2 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
never good
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in Sion over the whole year is 6°C. July is the hottest month, with highs of about 18°C; January is the coldest, with lows of about -4°C. Sion has no sharply defined rainy season: the chance of rain on a given day runs from 15% in October, the driest month, to 23% in May, the wettest. Winds in Sion are highest in January, averaging 3.0 m/s (11 km/h), and lightest in September, at 2.3 m/s (8 km/h). The prevailing wind is from the S. The clearest skies in Sion come in August, when the sky is typically 49% covered; November is the cloudiest month, at 62%.
Month by month Sion climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
-1°C
-4°C
-6°C
22%
59%
3.0 m/s
0
0
3
February
2°C
-2°C
-3°C
17%
56%
2.9 m/s
0
0
11
March
4°C
-1°C
-1°C
20%
54%
3.0 m/s
1
0
18
April
7°C
1°C
2°C
18%
55%
2.9 m/s
7
0
35
May
10°C
5°C
6°C
23%
62%
2.7 m/s
19
1
49
June
16°C
10°C
13°C
21%
53%
2.7 m/s
44
7
62
July
18°C
12°C
15°C
18%
50%
2.7 m/s
52
11
65
August
17°C
11°C
15°C
17%
49%
2.4 m/s
51
12
63
September
14°C
8°C
11°C
16%
54%
2.3 m/s
35
3
62
October
10°C
5°C
6°C
15%
54%
2.7 m/s
14
0
51
November
3°C
0°C
-1°C
19%
62%
2.6 m/s
1
0
19
December
0°C
-2°C
-4°C
23%
58%
2.9 m/s
0
0
5
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Sion weather by season
Year round, Sion has days of about -1°C at their warmest in January, its coolest month, and 18°C in July, its warmest; the coolest hours of the day run from -4°C to 12°C through the year, and the average temperature over the year is 6°C around the clock. Rain is most likely around May and least likely around October. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Sion weather in winterDecember to February
High 0°CLow -2°CRain 20%
Winter in Sion has typical daily highs of about 0°C and lows of about -2°C, with a 20% chance of rain on a given day.
Sion weather in springMarch to May
High 7°CLow 2°CRain 20%
Spring in Sion has typical daily highs of about 7°C and lows of about 2°C, with a 20% chance of rain on a given day.
Sion weather in summerJune to August
High 17°CLow 11°CRain 18%
Summer in Sion has typical daily highs of about 17°C and lows of about 11°C, with a 18% chance of rain on a given day.
Sion weather in autumnSeptember to November
High 9°CLow 4°CRain 17%
Autumn in Sion has typical daily highs of about 9°C and lows of about 4°C, with a 17% chance of rain on a given day.
When is the rainy season in Sion?
Sion has no sharply defined rainy season: the chance of rain on a given day runs from 15% in October, the driest month, to 23% in May, the wettest.
What time of year is Sion windiest?
Winds in Sion are highest in January, averaging 3.0 m/s (11 km/h), and lightest in September, at 2.3 m/s (8 km/h). The prevailing wind is from the S.
What is the average temperature in Sion year round?
The average temperature in Sion over the whole year is 6°C. July is the hottest month, with highs of about 18°C; January is the coldest, with lows of about -4°C.