Climate and monthly weather forecast
Big Sky, MT

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Vast fields and planted forests near the scenic mountainous region in Big Sky, Montana
Vast fields and planted forests near the scenic mountainous region in Big Sky, Montana

The climate of Big Sky

Big Sky, Montana is marked by a Humid Continental climate, falling into the Dfb category of the Köppen climate classification. Geographically placed in the Northern Hemisphere, the weather of this mountainous town varies widely throughout the year, with barely any respite from the variations.

The place experiences all four seasons, with consistent monthly alterations in the weather conditions. Monthly average temperatures fluctuate from a low of 9.9°F (-12.3°C) in January to a significant high of 74.8°F (23.8°C) in July, illustrating a clear diffusion of cold and warmth. Relative humidity also sees a reduction through the year, starting at 90% in January and decreasing to 51% in August, emphasizing on the dry nature of the summer months.

Rainfall in Big Sky is not an uncommon phenomenon, with the maximum average monthly precipitation of 2.91" (74mm) occurring in April and May. There are significant variations in the rainfall days, peaking to 16.6 days in June. In contrast, December witnesses an average rainfall of just 1.34" (34mm), spanning around 6.3 days. Moreover, snowfall is a regular occurrence in the winter months, highly noticeable from December to February.

The best time to visit Big Sky

The best time to visit Big Sky would greatly depend on the activities visitors are keen to indulge in. If skiing or other winter sports are the activities of choice, then planning a visit between December and February is most apposite, as average snowfall ranges from 11.1" (282mm) to 16.93" (430mm) during these months.

On the other hand, summer in Big Sky is absolutely delightful for those who prefer milder climates, green landscapes, and outdoor music festivals. With temperatures ranging from 64°F (17.8°C) to 74.8°F (23.8°C) and lower humidity levels, the months of June, July, and August offer just the right conditions to explore the Montana wilderness.

The worst time to visit Big Sky

Big Sky's terrain and climate conditions do not lead to any specific unsuitable period for visitation. However, travelers aiming to avoid extreme weather changes or significant snowfall should steer clear of the winter months, particularly from December to February. During these months, average low temperatures can drop to a harsh 7.9°F (-13.4°C) and snowfall reaches up to 19.1 days in January.

Spring weather in Big Sky

The spring months in Big Sky present quite a variety in terms of weather conditions. Throughout March, April, and May, temperatures progressively rise from 32.9°F (0.5°C) to 52°F (11.1°C). The spring season also brings sizeable precipitation, with rainfall volumes reaching up to 2.91" (74mm) in April and May. The town equally observes an upsurge in daylight hours during this period, extending from 12 hours in March to about 14.9 hours by the end of May.

Summer weather in Big Sky

Summer in Big Sky appears to be the driest period of the year. Humidity levels drop significantly during these months. While temperatures hover between 64°F (17.8°C) in June and 74.8°F (23.8°C) in July, comparatively low rainfall levels are observed, ranging between 1.18" (30mm) in July to 2.68" (68mm) in June, highlighting the tranquillity of the season.

Autumn weather in Big Sky

As the year progresses into September, October, and November, Big Sky experiences a cool and crisp autumn. Average temperatures plunge from the pleasant 63.5°F (17.5°C) in September to a chilly 32.2°F (0.1°C) in November. Rainfall days are moderate during the autumn months, but the town experiences a steady increase in relative humidity.

Winter weather in Big Sky

Winter sets in Big Sky by December and stretches till February. This period is characterized by severe cold, with average low temperatures plummeting down to 7.9°F (-13.4°C) in January. These months also witness considerable snowfall, with snowfall days reaching up to 21 in March. Despite these challenging conditions, winter proves to be a popular season among visitors with a penchant for skiing and snowboarding.

Weather in January

In Big Sky, January weather is defined by its chilly temperatures and a significant amount of snow. The lowest temperatures for the year occur in January, dipping to 9.9°F (-12.3°C), reinforcing its position as the coldest month. Weather in January »

Weather in February

The weather in Big Sky in February does not deviate greatly from January's conditions. A slight increase in temperature is recorded, yet the city remains firmly in the grip of winter. Snow continues to be a prominent feature of February's weather, facilitating the continuation of winter sports activities. Weather in February »

Weather in March

March inaugurates the shift towards spring in Big Sky, marked by increments in temperature and daylight hours. It struggles to shake off winter completely, with average highs reaching only to 32.9°F (0.5°C) and snow still appearing familiarly. Weather in March »

Weather in April

In Big Sky, April weather further emphasizes the transition into spring. Temperatures begin to climb more noticeably now, with highs fluctuating around 40.1°F (4.5°C). However, snow remains a consistent feature, lightly dusting the city before the melting begins in earnest. Weather in April »

Weather in May

May arrives in Big Sky heralding the arrival of warmer temperatures. The landscape begins to shed its winter coverage, showcasing its vibrant spring flora. Rain becomes the preferred form of precipitation, replacing the snow that dominated the previous months. Weather in May »

Weather in June

June solidifies summer's presence in Big Sky, presenting warmer days and shedding the final vestiges of snow. The pleasant weather conditions set the stage for a host of outdoor activities. The beautiful surroundings under the longest daylight span of the year attract both residents and visitors. Weather in June »

Weather in July

July is the zenith of summer in Big Sky, showcasing the iconic Montana summer at its best. Temperature peaks at a high of 74.8°F (23.8°C), the highest average for the year. The fruitful blend of clear blue skies, balmy weather conditions, and longer sunshine hours solidify July as the perfect month for outdoor activities. Weather in July »

Weather in August

The weather in Big Sky remains comfortably warm in August, encouraging the continuation of summer activities. Although temperatures begin to dip slightly from July's highs, the outdoor enjoyment doesn't taper off. It retains most of July's warmth while hinting at the upcoming transition to fall. Weather in August »

Weather in September

September ushers in autumn in Big Sky, adorned by the fall colors painting the Montana landscape. A clear drop in temperatures signifies the departure of summer. Still, it optimizes the comfortable condition between summer's heat and winter's chill. Weather in September »

Weather in October

October in Big Sky brings about a stronger presence of autumn, coupled with a quick return to colder temperatures. The charm of fall becomes even more pronounced, rendering the atmosphere picture-perfect. However, winter begins to sneak in, with snow making a comeback towards the month's end. Weather in October »

Weather in November

The arrival of November in Big Sky indicates the steady encroachment of winter. Temperatures continue to drop, with average highs hovering around 32.2°F (0.1°C). The snow that heralded its arrival in October becomes a more frequent visitor, spreading a white carpet over the region. Weather in November »

Weather in December

December brings Big Sky full circle as it plunges back into the height of winter. The thermometer continues to drop, averaging highs of only 22.5°F (-5.3°C). Thunderous snowfall covers the town, preparing for an array of winter activities once again. Weather in December »
Updated: Jul 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the most humid months?

January and February, with an average relative humidity of 90%, are most humid months.

How much does it rain?

Throughout the year, there are 116.1 rainfall days, and 23.5" (597mm) of precipitation is accumulated.

When does it snow?

Months with snowfall are January through December.

How many days does it snow in Big Sky?

In Big Sky, during the entire year, snow falls for 151.6 days and aggregates up to 124.06" (3151mm) of snow.

What is the month with the least sunshine?

With an average of 4.7h of sunshine, January has the least sunshine of the year.

When is the lowest UV index?

The months with the lowest UV index are January and February, with an average maximum UV index of 1.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from MST to MDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from MDT to MST.

What is the wettest month?

The months with the most rainfall are April and May, with an average 2.91" (74mm) of precipitation.

When does it snow the most?

April is the month with the most snowfall. Snow falls for 20.5 days and accumulates 19.88" (505mm) of snow.

When are the longest days?

June has the longest days of the year, with an average of 15h and 36min of daylight.

What month is the hottest?

Big Sky's warmest weather arrives in July, when temperatures average a high of 74.8°F (23.8°C) and a low of 44.6°F (7°C).

What is the driest month?

July is the month with the least rainfall. Rain falls for 12.5 days and accumulates 1.18" (30mm) of precipitation.

What month has the most sunshine?

The month with the most sunshine is July, with an average of 11.7h of sunshine.

When is the highest UV index?

The month with the highest UV index is July, with an average maximum UV index of 5.

What is the least humid month?

August is the least humid month, with an average relative humidity of 51%.

When it does not snow?

The month with the least snowfall is August, when snow falls for 0.3 days and typically aggregates up to 0.08" (2mm) of snow.

What are the coldest months?

In Big Sky, December is the coldest month, with temperatures averaging a high of 22.5°F (-5.3°C) and a low of 7.9°F (-13.4°C).

What is the month with the shortest days?

December has the shortest days of the year, with an average of 8h and 48min of daylight.

Average temperature
Big Sky, MT

Average temperature - Big Sky, MT

The warmest month (with the highest average high temperature) is July (74.8°F).
The month with the lowest average high temperature is December (22.5°F).

The month with the highest average low temperature is August (45.1°F).
The coldest month (with the lowest average low temperature) is December (7.9°F).

Average pressure
Big Sky, MT

Average pressure - Big Sky, MT

The month with the highest atmospheric pressure is January (30.22"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed
Big Sky, MT

Average wind speed - Big Sky, MT

The windiest month (with the highest average wind speed) is January (7.1mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).

Average humidity
Big Sky, MT

Average humidity - Big Sky, MT

The months with the highest relative humidity are January and February (90%).
The month with the lowest relative humidity is August (51%).

Average rainfall
Big Sky, MT

Average rainfall - Big Sky, MT

The wettest months (with the highest rainfall) are April and May (2.91").
The driest month (with the least rainfall) is July (1.18").

Average rainfall days
Big Sky, MT

Average rainfall days - Big Sky, MT

The month with the highest number of rainy days is June (16.6 days).
The month with the least rainy days is February (4.3 days).

Average snowfall
Big Sky, MT

Average snowfall - Big Sky, MT

The month with the highest snowfall is April (19.88").
The month with the least snowfall is August (0.08").

Average snowfall days
Big Sky, MT

Average snowfall days - Big Sky, MT

The month with the highest number of snowfall days is March (21 days).
The month with the least snowfall days is August (0.3 days).

Average daylight / Average sunshine
Big Sky, MT

Average daylight / Average sunshine - Big Sky, MT

The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).

The month with the most sunshine is July (Average sunshine: 11h and 42min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).

Average sunshine days
Big Sky, MT

Average sunshine days - Big Sky, MT

The month with the most sunshine days is September (14.5 days).
The month with the least sunshine days is May (5.7 days).

Average visibility
Big Sky, MT

Average visibility - Big Sky, MT

The months with the highest visibility are June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, March, April and December (4mi).

Big Sky, Montana, USA

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