Big Sky, nestled in the Rocky Mountains of Montana, features a high-altitude continental climate with cold, snowy winters and mild, short summers. The area experiences dramatic seasonal contrasts, abundant sunshine, and significant day-night temperature swings, making it a premier destination for skiing, hiking, and year-round outdoor adventures in a pristine alpine setting.
The best times to travel section shows how the months compare for a visit, so you can find the time of year that fits what you want to do.
Background colours of the months:
The colour shows the typical temperature: yellow (hot), green (mild) and blue (cold). How strong the colour is shows the travel season: full colour means high season, soft colour means shoulder season and soft-striped means off season.
Weather symbols:
Each month has one symbol showing what the weather is typically like, such as hot and sunny, freezing or a rainy or snowy season. Use them to quickly spot months that match the weather you want, or to avoid the ones that don't.
Crowdedness:
The people icon shows how busy the place usually is. The more people, the more crowded it gets.
Additional notes:
The grey info boxes point out special things worth knowing, like recurring weather issues or seasonal events.
Big Sky’s climate is shaped by its elevation (over 2,100 metres/7,200 feet) and mountainous location, resulting in four distinct seasons and large temperature variations. Winters (November–April) are long, cold, and snowy, with average highs of –2°C to 2°C and lows around –13°C to –7°C in January. Snowfall is abundant, averaging 160–170 inches (400–430 cm) annually, with the heaviest snow from December to March. Despite the cold, Big Sky enjoys over 300 days of sunshine per year, and winter days are often bright and crisp. Winds are generally moderate, but mountain gusts can occur, especially during storms.
Summers (June–August) are short, mild, and sunny, with average highs of 22–25°C in July and August and cool nights around 7–10°C. Rainfall is moderate, peaking in June with brief afternoon thunderstorms, while humidity remains low. Spring and autumn are transitional, with rapidly changing weather, melting snow or early frosts, and temperatures ranging from 5–18°C. Big Sky’s climate supports a long ski season, lush summer meadows, and a wealth of outdoor activities. Daylight lasts up to 15 hours in midsummer and drops to 9 hours in winter, with clear skies and spectacular mountain views year-round.
| Average climate data for Big Sky, United States | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Average maximum temperature (°C) | -4 | -4 | 0 | 4 | 11 | 18 | 24 | 23 | 17 | 7 | -0 | -5 | 24 |
| Average minimum temperature (°C) | -12 | -12 | -8 | -5 | -1 | 3 | 7 | 7 | 4 | -2 | -8 | -14 | -14 |
| Average precipitation (mm) | 39 | 52 | 50 | 74 | 74 | 68 | 30 | 36 | 46 | 51 | 44 | 34 | 598 |
| Average rainfall days (days) | 5 | 4 | 8 | 9 | 16 | 17 | 12 | 13 | 11 | 8 | 5 | 6 | 116 |
| Average snowfall (mm) | 320 | 424 | 397 | 506 | 257 | 136 | 9 | 2 | 126 | 312 | 363 | 282 | 3,134 |
| Average snowfall days (days) | 19 | 19 | 21 | 21 | 14 | 4 | 1 | 0 | 4 | 14 | 16 | 19 | 152 |
| Average relative humidity (%) | 91 | 90 | 88 | 84 | 74 | 63 | 51 | 52 | 56 | 71 | 84 | 90 | 74 |
| Average wind speed (km/h) | 11 | 10 | 10 | 9 | 8 | 9 | 8 | 8 | 8 | 10 | 11 | 11 | 9 |
| Average daily daylight hours (h) | 9 | 10 | 12 | 13 | 14 | 15 | 15 | 14 | 12 | 10 | 9 | 8 | 12 |
| Average daily sunshine hours (h) | 4 | 4 | 6 | 7 | 9 | 10 | 11 | 11 | 9 | 6 | 5 | 4 | 7 |
| Average cloud coverage (%) | 55 | 61 | 56 | 50 | 41 | 31 | 18 | 19 | 23 | 34 | 46 | 56 | 41 |
| Average UV index | 1 | 1 | 2 | 2 | 3 | 4 | 5 | 4 | 3 | 2 | 2 | 2 | 3 |
The best time to visit Big Sky depends on your interests: December to March is ideal for winter sports, with deep snow and lively ski resorts. For hiking, biking, and fishing, July and August offer warm days, cool nights, and abundant sunshine, with wildflowers and mountain scenery at their peak.
The least favourable time to visit is in late April to early June, when snowmelt creates muddy conditions and some trails may be inaccessible. Early spring and late autumn can also bring unpredictable weather and fewer activities, as the area transitions between main tourist seasons.
Big Sky has a high-altitude continental climate with cold, snowy winters and mild, short summers. Winters average highs of –2°C to 2°C, while summer highs reach 22–25°C. Sunshine is abundant, and weather can change rapidly.
The best time for skiing is from December to March, when snow cover is deepest and the ski resorts are in full swing. The ski season typically runs from late November to April.
Summer highs in Big Sky reach 22–25°C in July and August, with cool nights around 7–10°C. Afternoon thunderstorms are possible, but most days are sunny and comfortable for outdoor activities.
Yes, Big Sky receives 160–170 inches (400–430 cm) of snow annually, with the heaviest snowfall from December to March. Snow can fall from October to May, supporting a long ski season.
Big Sky enjoys over 300 days of sunshine per year. Even in winter, the sun is strong due to the high altitude, so sunglasses and sun cream are recommended year-round.
Pack layers for large day-night temperature swings, sun protection for high UV, and waterproof boots for winter or spring. Even in summer, bring a jumper or jacket for cool evenings and occasional rain.
Spring and autumn are quieter, with fewer crowds and beautiful scenery, but weather can be unpredictable. Some trails may be muddy in spring, and some attractions may have reduced hours between the main seasons.
The warmest month, with the highest average maximum temperature, is July (23.8 °C). The month with the lowest average maximum temperature is December (-5.2 °C). Overall, the average maximum temperature over the whole year is 7.7 °C.
The month with the highest average minimum temperature is August (7.2 °C). The coldest month, with the lowest average minimum temperature, is December (-13.5 °C). Overall, the average minimum temperature over the whole year is -3.5 °C.
The wettest month, with the highest amount of precipitation, is May (74.1 mm). The driest month, with the least amount of precipitation, is July (30.2 mm). Over the whole year there are 597.6 mm of rainfall on average.
The month with the most days of rain is June (16.7 days). The month with the fewest days of rain is February (4.4 days). Over the whole year there are 116 days of rain on average.
The month with the most snowfall is April (506.2 mm). The month with the least snowfall is August (2 mm). Over the whole year there are 3,133.7 mm of snowfall on average.
The month with the most days of snowfall is March (21.1 days). The month with the fewest days of snowfall is August (0.3 days). Over the whole year there are 151.9 days of snowfall on average.
The month with the highest average relative humidity is January (91 %). The month with the lowest average relative humidity is July (51 %). The overall average relative humidity over the whole year is 74.5 %.
The windiest month, with the highest average wind speed, is January (11.4 km/h). The calmest month, with the lowest average wind speed, is August (7.9 km/h). The overall average wind speed over the whole year is 9.5 km/h.
The month with the cloudiest skies, so the highest cloud coverage, is February (60.8 %). The month with the clearest skies, so the lowest cloud coverage, is July (17.6 %). Over the whole year there is an average cloud coverage of 40.7 %.
The month with the longest days, so the most daylight, is June (Average daylight: 15.1 h). The month with the shortest days, so the least daylight, is December (Average daylight: 8.1 h). Over the whole year there are 11.8 h of daylight per day on average.
The month with the most sunshine per day is July (Average sunshine: 11.1 h). The month with the least sunshine per day is February (Average sunshine: 4.1 h). Over the whole year there are 7.2 h of sunlight per day on average.
The month with the highest average UV index is July (UV index: 5). The months with the lowest average UV index are January and February (UV index: 1). Over the whole year the average UV index is 2.6.
