The best times to visit Sion for ideal weather are

May 7th to October 14th

based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.

 

 


Other Sion Travel Info

Weather in Sion

Temperature

Average temperatures in Sion vary greatly. Considering humidity, temperatures feel cold for about half of the year and otherwise nice with a fair chance of precipitation about half of the year. The area is somewhat temperate — in the 43rd percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit Sion, the hottest months are July, August, and then June. See average monthly temperatures below. The warmest time of year is generally early August where highs are regularly around 82.2°F (27.9°C) with temperatures rarely dropping below 59.2°F (15.1°C) at night.

Sion Temperatures (Fahrenheit)

Key
High
Average
Low

Sion Temperatures (Celsius)

Key
High
Average
Low

“Feels-Like” Temperatures

The way we experience weather isn’t all about temperature. Higher temperatures affect us much more at higher humidity, and colder temperatures feel piercing with high winds. Our perceived temperatures factor in humidity and wind chill to better represent how hot or cold the day feels to a person.

Sion Perceived Temperature (F)

Key
High
Average
Low

Sion Perceived Temperature (C)

Key
High
Average
Low

 

Average Sion Temperatures by Month

Daily highs (averaged for the month) usually give the best indication of the weather. A significantly lower mean and low generally just means it gets colder at night.

Show Fahrenheit

Month Avg. High (°F) Avg. Mean (°F) Avg. Low (°F)
Jan 41.7 33.6 27.1
Feb 45.6 35.5 27.9
Mar 56.6 44.8 35
Apr 66.4 54 42.7
May 71.5 59.7 48.9
Jun 78.4 66.4 55.6
Jul 81.5 68.9 58
Aug 79.9 67.9 57.5
Sep 72 60.5 50.6
Oct 63.1 51.9 43.1
Nov 51.8 42.1 34.6
Dec 41.4 33.8 27.5

Show Celsius

Month Avg. High (°C) Avg. Mean (°C) Avg. Low (°C)
Jan 5.4 0.9 -2.7
Feb 7.6 1.9 -2.3
Mar 13.7 7.1 1.7
Apr 19.1 12.2 5.9
May 21.9 15.4 9.4
Jun 25.8 19.1 13.1
Jul 27.5 20.5 14.4
Aug 26.6 19.9 14.2
Sep 22.2 15.8 10.3
Oct 17.3 11.1 6.2
Nov 11 5.6 1.4
Dec 5.2 1 -2.5

 


 

Precipitation (Rain or Snow)

If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Sion are March, April, and then October. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around early April. For example, on the week of April 2nd there are no days of precipitation on average. By contrast, it’s most likely to rain or snow in early December with an average of 2 days of significant precipitation the week of December 3rd.

When can you find snow in Sion? Weather stations report large amounts of snow likely to be deepest around November, especially close to mid to late November. The best time to ski (if at all) in Sion is often around around November 19th when fresh powder is deepest. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.

Chance of Precipitation

The graph below shows the % chance of rainy and snowy days in Sion.

Key
Days with precipitation

Snow on the Ground

The graph below shows the average snow on the ground in Sion (in).

Key
Snow depth

Average Rain and Snow by Month

Show Inches

Month Daily Chance of Rain Average Snow Depth (in) Total Precipitation (in)
Jan 18% 2.4 2.1
Feb 13% 1.9 1.2
Mar 10% 3 1.1
Apr 10% 0 0.9
May 16% 0 2.6
Jun 16% 0 1.7
Jul 18% 0 2.8
Aug 18% 0 2.2
Sep 15% 0 1.2
Oct 12% 0.8 1.2
Nov 15% 4.9 2
Dec 22% 4.4 3.2

Show Centimeters

Month Daily Chance of Rain Average Snow Depth (cm) Total Precipitation (cm)
Jan 18 6.1 5.3
Feb 13 4.8 3
Mar 10 7.6 2.8
Apr 10 0 2.3
May 16 0 6.6
Jun 16 0 4.3
Jul 18 0 7.1
Aug 18 0 5.6
Sep 15 0 3
Oct 12 2 3
Nov 15 12.4 5.1
Dec 22 11.2 8.1

 

Humidity and Wind

Sion has some very humid months, with other moderately humid months on the other side of the year. The least humid month is April (45.2% relative humidity), and the most humid month is December (74%).

Wind in Sion is usually calm. The windiest month is June, followed by July and May. June’s average wind speed of around 5.6 knots (6.5 MPH or 10.4 KPH) is considered “a light breeze.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in mid June where average top sustained speeds reach 16.5 knots, which is considered a moderate breeze.

Relative Humidity (%)

The graph below shows the average % humidity by month in Sion.

Key
Avg. Relative Humidity

Wind

The graph below shows wind speed (max and average) in knots.

Key
Max Sustained Wind
Average Daily Wind

Average Wind Speeds

Show Wind Speeds

All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.

Month Avg. Wind Avg. Wind Feel Sustained High Wind High Wind Feel
Jan 2.9 Barely noticeable 7.6 Gentle breeze
Feb 3.4 Barely noticeable 9.7 Gentle breeze
Mar 4.8 Light breeze 14.5 Gentle breeze
Apr 5.2 Light breeze 15.1 Significant breeze
May 5.3 Light breeze 15.1 Gentle breeze
Jun 5.6 Light breeze 15.8 Significant breeze
Jul 5.4 Light breeze 16 Gentle breeze
Aug 4.9 Light breeze 14.9 Significant breeze
Sep 4.5 Light breeze 13.8 Gentle breeze
Oct 3.5 Barely noticeable 10.9 Gentle breeze
Nov 2.9 Barely noticeable 8 Gentle breeze
Dec 2.7 Barely noticeable 7.4 Gentle breeze

Show Relative Humidity by Month

Month Avg. Relative Humidity
Jan 69.9%
Feb 59.5%
Mar 47.7%
Apr 45.2%
May 50.4%
Jun 50.7%
Jul 52.3%
Aug 55.8%
Sep 60.3%
Oct 65.5%
Nov 67.9%
Dec 74%

 

Is it Safe to Travel to Sion?

Our best data indicates this area is generally safe. As of Dec 04, 2023 there are no travel advisories or warnings for Switzerland; exercise normal security precautions. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Nov 14, 2023.


 

The Busiest and Least Crowded Months

The busiest month for tourism in Sion, Switzerland is June, followed by August and April. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit Sion in October. Those willing to visit at these times will likely find it the least expensive month.

Estimated Tourism by Month

 

Most Popular Months to Visit

Key
Tourists Seeking Accommodations

Tourism graph is based on Google searches for services used by tourists relative to the rest of the year. Tourism data for this area is somewhat extrapolated based on nearby areas. Displayed data is calculated relative to the peak, so a score of 53 in October means 53% of the tourists vs. June.

 

 

Overall Sion Travel Experience by Season

Spring (March through May)

Humidity and temperatures combine to make this season feel moderately cold. Highs range from 75.2°F (24°C) and 52.9°F (11.6°C) with warmer temperatures in the later months. Rain is rare with 3 to 5 days of significant precipitation per month. Spring is the second busiest for tourism, which makes it a good time for those looking for things to do.

Summer (June through August)

The middle-year months have very comfortable weather with high temperatures that are comfortable. These months see moderate precipitation with 5 to 6 days of precipitation per month. June – August is the busiest season for tourism in Sion, so lodging and other accommodations may cost more than usual.

Fall (September through November)

Fall daily highs range from 75.8°F (24.3°C) and 44.6°F (7°C), which will feel chilly given the humidity and wind. It rains or snows a significant amount: 4 to 5 days per month. Tourism is the slowest during these months due to the weather, so hotels may be affordably priced.

Winter (December through February)

Weather is far too cold this time of year in Sion to be enjoyable for warm weather travelers. The average high during this season is between 52.9°F (11.6°C) and 40°F (4.4°C). On average, it rains or snows a fair amount: 4 to 7 times per month. These times of year are fairly slow with tourists.

 

Best Times to Travel› Switzerland › Sion, Switzerland