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Big Sky, Montana climate
Dfc Subarctic
Big Sky has a strongly seasonal cold-temperate climate (Subarctic, Köppen Dfc). The hottest month is July with an average daily high near 28°C, while the coldest is December averaging around −16°C at night. Around 620 mm of precipitation falls each year, peaking in December (70 mm) and easing off in July (27 mm).
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation · 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)Big Sky climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | −2 | 1 | 7 | 11 | 16 | 21 | 28 | 27 | 20 | 11 | 3 | −3 |
| Avg temp (°C) | −9 | −7 | −2 | 2 | 7 | 11 | 16 | 14 | 9 | 3 | −4 | −10 |
| Avg low (°C) | −16 | −16 | −11 | −6 | −2 | 1 | 4 | 2 | −2 | −6 | −11 | −16 |
| Precipitation (mm) | 62 | 60 | 55 | 62 | 63 | 50 | 27 | 27 | 33 | 48 | 63 | 70 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°C) | −2 | 1 | 7 | 11 | 16 | 21 |
| Avg temp (°C) | −9 | −7 | −2 | 2 | 7 | 11 |
| Avg low (°C) | −16 | −16 | −11 | −6 | −2 | 1 |
| Precipitation (mm) | 62 | 60 | 55 | 62 | 63 | 50 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°C) | 28 | 27 | 20 | 11 | 3 | −3 |
| Avg temp (°C) | 16 | 14 | 9 | 3 | −4 | −10 |
| Avg low (°C) | 4 | 2 | −2 | −6 | −11 | −16 |
| Precipitation (mm) | 27 | 27 | 33 | 48 | 63 | 70 |
How often — frequency of weather events
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 9 | 9 | 8 | 8 | 7 | 6 | 4 | 4 | 4 | 6 | 8 | 9 |
| Days with high ≥ 32°C (days) | — | — | — | — | — | 0.3 | 3 | 1 | 0.1 | 0.1 | — | — |
| Days with low ≤ 0°C (days) | 22 | 21 | 22 | 21 | 18 | 9 | 2 | 7 | 16 | 22 | 22 | 24 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 9 | 9 | 8 | 8 | 7 | 6 |
| Days with high ≥ 32°C (days) | — | — | — | — | — | 0.3 |
| Days with low ≤ 0°C (days) | 22 | 21 | 22 | 21 | 18 | 9 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 4 | 4 | 4 | 6 | 8 | 9 |
| Days with high ≥ 32°C (days) | 3 | 1 | 0.1 | 0.1 | — | — |
| Days with low ≤ 0°C (days) | 2 | 7 | 16 | 22 | 22 | 24 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 67 | 67 | 71 | 71 | 68 | 58 | 41 | 42 | 46 | 58 | 67 | 68 |
| Relative humidity (%) | 99 | 99 | 95 | 83 | 73 | 67 | 55 | 49 | 54 | 68 | 87 | 98 |
| Wind speed (m/s) | 0.6 | 0.7 | 0.7 | 0.6 | 0.4 | 0.2 | 0.2 | 0.2 | 0.3 | 0.3 | 0.5 | 0.6 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 67 | 67 | 71 | 71 | 68 | 58 |
| Relative humidity (%) | 99 | 99 | 95 | 83 | 73 | 67 |
| Wind speed (m/s) | 0.6 | 0.7 | 0.7 | 0.6 | 0.4 | 0.2 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 41 | 42 | 46 | 58 | 67 | 68 |
| Relative humidity (%) | 55 | 49 | 54 | 68 | 87 | 98 |
| Wind speed (m/s) | 0.2 | 0.2 | 0.3 | 0.3 | 0.5 | 0.6 |
Methodology & sources
Temperature & precipitation — 1991–2020 normals computed from 22 years of daily observations at West Yellowstone, a weather station, about 73 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.