| Average climate data for Sun Valley, United States | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Average maximum temperature (°C) | -3 | -3 | -0 | 4 | 11 | 17 | 23 | 23 | 18 | 9 | 2 | -4 | 23 |
| Average minimum temperature (°C) | -13 | -12 | -8 | -5 | 1 | 5 | 10 | 10 | 6 | -1 | -7 | -13 | -13 |
| Average precipitation (mm) | 40 | 50 | 51 | 38 | 45 | 31 | 11 | 13 | 22 | 27 | 28 | 42 | 397 |
| Average rainfall days (days) | 6 | 7 | 11 | 12 | 15 | 11 | 6 | 7 | 9 | 9 | 7 | 7 | 108 |
| Average snowfall (mm) | 321 | 381 | 319 | 146 | 37 | 5 | 0 | 0 | 14 | 58 | 173 | 308 | 1,762 |
| Average snowfall days (days) | 14 | 15 | 16 | 11 | 3 | 1 | 0 | 0 | 0 | 3 | 11 | 14 | 88 |
| Average relative humidity (%) | 84 | 88 | 84 | 75 | 65 | 54 | 38 | 37 | 43 | 62 | 74 | 83 | 66 |
| Average wind speed (km/h) | 7 | 8 | 9 | 10 | 9 | 10 | 10 | 9 | 9 | 8 | 8 | 7 | 9 |
| Average daily daylight hours (h) | 9 | 10 | 12 | 13 | 14 | 15 | 15 | 13 | 12 | 11 | 9 | 9 | 12 |
| Average daily sunshine hours (h) | 5 | 6 | 7 | 9 | 10 | 11 | 12 | 11 | 9 | 7 | 6 | 5 | 8 |
| Average cloud coverage (%) | 39 | 45 | 43 | 34 | 27 | 20 | 11 | 10 | 16 | 22 | 30 | 41 | 28 |
| Average UV index | 2 | 1 | 2 | 2 | 3 | 5 | 5 | 4 | 3 | 2 | 2 | 2 | 3 |
The warmest month, with the highest average maximum temperature, is July (23.3 °C). The month with the lowest average maximum temperature is December (-3.9 °C). Overall, the average maximum temperature over the whole year is 8.1 °C.
The month with the highest average minimum temperature is August (10.3 °C). The coldest month, with the lowest average minimum temperature, is January (-13.2 °C). Overall, the average minimum temperature over the whole year is -2.2 °C.
The wettest month, with the highest amount of precipitation, is March (51.3 mm). The driest month, with the least amount of precipitation, is July (11 mm). Over the whole year there are 397.5 mm of rainfall on average.
The month with the most days of rain is May (14.8 days). The month with the fewest days of rain is July (6 days). Over the whole year there are 108.2 days of rain on average.
The month with the most snowfall is February (380.5 mm). The months with the least snowfall are July and August (0 mm). Over the whole year there are 1,761.6 mm of snowfall on average.
The month with the most days of snowfall is March (16.1 days). The months with the fewest days of snowfall are July and August (0 days). Over the whole year there are 87.8 days of snowfall on average.
The month with the highest average relative humidity is February (87.8 %). The month with the lowest average relative humidity is August (37.2 %). The overall average relative humidity over the whole year is 65.7 %.
The windiest month, with the highest average wind speed, is July (10.2 km/h). The calmest month, with the lowest average wind speed, is January (7.3 km/h). The overall average wind speed over the whole year is 8.8 km/h.
The month with the cloudiest skies, so the highest cloud coverage, is February (45.2 %). The month with the clearest skies, so the lowest cloud coverage, is August (10.2 %). Over the whole year there is an average cloud coverage of 28.1 %.
The month with the longest days, so the most daylight, is June (Average daylight: 15 h). The month with the shortest days, so the least daylight, is December (Average daylight: 9 h). Over the whole year there are 11.9 h of daylight per day on average.
The month with the most sunshine per day is July (Average sunshine: 12.1 h). The month with the least sunshine per day is January (Average sunshine: 5.1 h). Over the whole year there are 8.2 h of sunlight per day on average.
The months with the highest average UV index are June and July (UV index: 5). The month with the lowest average UV index is February (UV index: 1). Over the whole year the average UV index is 2.8.
