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Sun Valley, Idaho climate
Dsb Mediterranean-influenced warm-summer humid continental
Sun Valley has a seasonal cold-temperate climate (Mediterranean-influenced warm-summer humid continental, Köppen Dsb). The hottest month is July with an average daily high near 81°F, while the coldest is January averaging around 8°F at night. Precipitation totals about 17 inches a year and is strongly seasonal — December alone averages 2.7 inches while August barely receives 0.45 inches. Snowfall is heavy (103 inches of snow per year on average).
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation split into rain and snow · 1991–2020 normals · hover a month for the exact figuresHours of sunshine per day
Estimated sunny hours each month — daylight length × clear-sky fraction · 1991–2020 monthly cloud cover (NASA POWER)Sun Valley climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 32 | 36 | 43 | 53 | 62 | 70 | 81 | 79 | 70 | 56 | 42 | 31 |
| Avg temp (°F) | 20 | 23 | 31 | 40 | 48 | 55 | 63 | 61 | 53 | 42 | 30 | 20 |
| Avg low (°F) | 8 | 11 | 18 | 27 | 34 | 39 | 45 | 43 | 36 | 27 | 17 | 9 |
| Precipitation (in) | 2.1 | 1.7 | 1.8 | 1.2 | 1.7 | 1.4 | 0.5 | 0.5 | 0.8 | 1.4 | 1.2 | 2.7 |
| Snowfall (in) | 28.5 | 18.3 | 10.4 | 3.7 | 0.2 | — | — | — | 0.0 | 1.7 | 10.2 | 29.7 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°F) | 32 | 36 | 43 | 53 | 62 | 70 |
| Avg temp (°F) | 20 | 23 | 31 | 40 | 48 | 55 |
| Avg low (°F) | 8 | 11 | 18 | 27 | 34 | 39 |
| Precipitation (in) | 2.1 | 1.7 | 1.8 | 1.2 | 1.7 | 1.4 |
| Snowfall (in) | 28.5 | 18.3 | 10.4 | 3.7 | 0.2 | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°F) | 81 | 79 | 70 | 56 | 42 | 31 |
| Avg temp (°F) | 63 | 61 | 53 | 42 | 30 | 20 |
| Avg low (°F) | 45 | 43 | 36 | 27 | 17 | 9 |
| Precipitation (in) | 0.5 | 0.5 | 0.8 | 1.4 | 1.2 | 2.7 |
| Snowfall (in) | — | — | 0.0 | 1.7 | 10.2 | 29.7 |
How often — frequency of weather events
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 9 | 8 | 8 | 6 | 7 | 7 | 4 | 4 | 4 | 5 | 6 | 10 |
| Days with high ≥ 90°F (days) | — | — | — | — | — | 0.2 | 2 | 0.9 | 0.0 | — | — | — |
| Days with low ≤ 32°F (days) | 31 | 27 | 30 | 24 | 12 | 4 | 1 | 1 | 8 | 23 | 28 | 30 |
| Days with snowfall ≥ 1 in (days) | 7 | 5 | 3 | 1 | 0.1 | — | — | — | — | 0.5 | 3 | 8 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 9 | 8 | 8 | 6 | 7 | 7 |
| Days with high ≥ 90°F (days) | — | — | — | — | — | 0.2 |
| Days with low ≤ 32°F (days) | 31 | 27 | 30 | 24 | 12 | 4 |
| Days with snowfall ≥ 1 in (days) | 7 | 5 | 3 | 1 | 0.1 | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 4 | 4 | 4 | 5 | 6 | 10 |
| Days with high ≥ 90°F (days) | 2 | 0.9 | 0.0 | — | — | — |
| Days with low ≤ 32°F (days) | 1 | 1 | 8 | 23 | 28 | 30 |
| Days with snowfall ≥ 1 in (days) | — | — | — | 0.5 | 3 | 8 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 59 | 61 | 64 | 63 | 61 | 50 | 35 | 35 | 39 | 48 | 58 | 61 |
| Relative humidity (%) | 84 | 82 | 74 | 64 | 58 | 51 | 39 | 36 | 41 | 54 | 70 | 83 |
| Wind speed (mph) | 3.7 | 4.2 | 4.7 | 5.0 | 4.8 | 4.9 | 4.7 | 4.5 | 4.2 | 4.2 | 3.8 | 3.6 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 59 | 61 | 64 | 63 | 61 | 50 |
| Relative humidity (%) | 84 | 82 | 74 | 64 | 58 | 51 |
| Wind speed (mph) | 3.7 | 4.2 | 4.7 | 5.0 | 4.8 | 4.9 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 35 | 35 | 39 | 48 | 58 | 61 |
| Relative humidity (%) | 39 | 36 | 41 | 54 | 70 | 83 |
| Wind speed (mph) | 4.7 | 4.5 | 4.2 | 4.2 | 3.8 | 3.6 |
Methodology & sources
Temperature & precipitation — 1991–2020 normals computed from 29 years of daily observations at Ketchum RS, a weather station, about 2 km from the city centre. The underlying daily records come from NOAA's global station network.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.