Average Weather in Vionnaz Switzerland
In Vionnaz, the summers are warm, the winters are very cold and wet, and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 28°F to 79°F and is rarely below 20°F or above 89°F.
Based on the tourism score, the best time of year to visit Vionnaz for warm-weather activities is from late June to mid September.
The warm season lasts for 3.3 months, from June 1 to September 11, with an average daily high temperature above 71°F. The hottest day of the year is August 4, with an average high of 79°F and low of 60°F.
The cold season lasts for 3.5 months, from November 19 to March 2, with an average daily high temperature below 47°F. The coldest day of the year is January 19, with an average low of 28°F and high of 40°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
In Vionnaz, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Vionnaz begins around June 20 and lasts for 3.0 months, ending around September 19. On July 23, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 63% of the time, and overcast or mostly cloudy 37% of the time.
The cloudier part of the year begins around September 19 and lasts for 9.0 months, ending around June 20. On May 8, the cloudiest day of the year, the sky is overcast or mostly cloudy 61% of the time, and clear, mostly clear, or partly cloudy 39% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Vionnaz varies throughout the year.
The wetter season lasts 3.1 months, from May 2 to August 6, with a greater than 35% chance of a given day being a wet day. The chance of a wet day peaks at 42% on May 25.
The drier season lasts 8.9 months, from August 6 to May 2. The smallest chance of a wet day is 27% on March 3.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 42% on May 25.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Vionnaz experiences some seasonal variation in monthly rainfall.
Rain falls throughout the year in Vionnaz. The most rain falls during the 31 days centered around June 2, with an average total accumulation of 3.7 inches.
The least rain falls around March 10, with an average total accumulation of 2.6 inches.
Average Monthly Rainfall
The sliding 31-day liquid-equivalent quantity of snowfall in Vionnaz does not vary significantly over the course of the year, staying within 0.1 inches of 0.1 inches throughout.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Vionnaz varies significantly over the course of the year. In 2018, the shortest day is December 21, with 8 hours, 36 minutes of daylight; the longest day is June 21, with 15 hours, 48 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:39 AM on June 16, and the latest sunrise is 2 hours, 36 minutes later at 8:15 AM on January 1. The earliest sunset is at 4:45 PM on December 11, and the latest sunset is 4 hours, 43 minutes later at 9:28 PM on June 26.
Daylight saving time (DST) is observed in Vionnaz during 2018, starting in the spring on March 25, lasting 7.1 months, and ending in the fall on October 28.
Sunrise & Sunset with Twilight and Daylight Saving Time
The perceived humidity level in Vionnaz, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
Humidity Comfort Levels
Average Wind Speed
The predominant average hourly wind direction in Vionnaz varies throughout the year.
The wind is most often from the north for 2.1 weeks, from April 16 to May 1, with a peak percentage of 30% on April 20. The wind is most often from the west for 4.3 months, from May 1 to September 11, with a peak percentage of 41% on July 5. The wind is most often from the south for 7.2 months, from September 11 to April 16, with a peak percentage of 53% on January 1.
Best Time of Year to Visit
To characterize how pleasant the weather is in Vionnaz throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Vionnaz for general outdoor tourist activities is from late June to mid September, with a peak score in the first week of August.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Vionnaz for hot-weather activities is from early July to mid August, with a peak score in the last week of July.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
The growing season in Vionnaz typically lasts for 7.5 months (229 days), from around March 26 to around November 11, rarely starting before March 4 or after April 18, and rarely ending before October 20 or after December 4.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in Vionnaz should appear around April 14, only rarely appearing before April 1 or after April 29.
Growing Degree Days
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.3 months, from May 10 to August 18, with an average daily incident shortwave energy per square meter above 6.0 kWh. The brightest day of the year is July 6, with an average of 7.1 kWh.
The darker period of the year lasts for 3.4 months, from October 29 to February 10, with an average daily incident shortwave energy per square meter below 2.5 kWh. The darkest day of the year is December 21, with an average of 1.4 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Vionnaz are 46.311 deg latitude, 6.901 deg longitude, and 1,444 ft elevation.
The topography within 2 miles of Vionnaz contains extreme variations in elevation, with a maximum elevation change of 3,862 feet and an average elevation above sea level of 2,127 feet. Within 10 miles also contains extreme variations in elevation (8,996 feet). Within 50 miles also contains extreme variations in elevation (14,649 feet).
The area within 2 miles of Vionnaz is covered by cropland (49%) and trees (40%), within 10 miles by trees (43%) and grassland (24%), and within 50 miles by trees (33%) and grassland (20%).
This report illustrates the typical weather in Vionnaz, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Vionnaz.
For each station, the records are corrected for the elevation difference between that station and Vionnaz according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Vionnaz is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Vionnaz and a given station.
The stations contributing to this reconstruction are: Sion (51%, 34 kilometers, east); Aéroport Genève-Cointrin (21%, 61 kilometers, west); Neuchatel (15%, 77 kilometers, north); and Bern-Belp Airport (14%, 81 kilometers, northeast).
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Time zones for aiports and weather stations are provided by AskGeo.com .