January 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

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. Highs of 25°F (-3.9°C) do not temper the biting cold much. January also marks a specific period for winter outdoor activities, with snow blanketing the city for most of the month. Visibility is also at its least, encouraging locals and tourists alike to embrace a slower, indoor lifestyle.

Temperature

The advent of January observes an average high-temperature of a still subzero cold 25°F (-3.9°C), nearly identical to December's 22.5°F (-5.3°C). Big Sky records an average nighttime low of 9.9°F (-12.3°C) in January.

Humidity

The months with the highest humidity are January and February, with an average relative humidity of 90%.

Rainfall

In Big Sky, in January, during 4.8 rainfall days, 1.54" (39mm) of precipitation is typically accumulated. Throughout the year, there are 116.1 rainfall days, and 23.5" (597mm) of precipitation is accumulated.

Snowfall

January through December are months with snowfall. In Big Sky, in January, during 18.9 snowfall days, 12.72" (323mm) of snow is typically accumulated. Throughout the year, there are 151.6 snowfall days, and 124.06" (3151mm) of snow is accumulated.

Daylight

The average length of the day in January in Big Sky is 9h and 13min.
On the first day of the month, sunrise is at 8:04 am and sunset at 4:53 pm. On the last day of January, sunrise is at 7:46 am and sunset at 5:30 pm MST.

Sunshine

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

UV index

January and February, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV rays for ordinary individuals.
Note: In January, the maximum UV index of 1 suggests this advice:
Though extended exposure to the sun typically does not concern most people, it is crucial to always shield children, infants, and those with sensitive skin. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.
Updated: Jul 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in Big Sky in January?

The high-temperature, in January, in Big Sky, records 25°F (-3.9°C), while the low-temperature is 9.9°F (-12.3°C).

What are the most humid months?

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

What is the average humidity in January in Big Sky?

The average relative humidity in January is 90%.

How many days does it rain in January?

In Big Sky, in January, it is raining for 4.8 days, with typically 1.54" (39mm) of accumulated precipitation.

How much does it snow in January?

In Big Sky, during January, snow falls for 18.9 days and regularly aggregates up to 12.72" (323mm) of snow.

How many hours of daylight does Big Sky have in January?

In January, the average day length is 9h and 13min.

When is the sunrise / sunset in January?

In January, on the first day of the month, sunrise is at 8:04 am and sunset at 4:53 pm. On the last day of the month, sunrise is at 7:46 am and sunset at 5:30 pm MST.

What is the month with the least sunshine in Big Sky?

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

How many hours of sunshine does Big Sky have in January?

In January, the average sunshine duration is 4.7h.

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.

What is the UV index reading in January?

In January, the average daily maximum UV index is 1. A UV Index reading of 2, and below, represents a minimal hazard to health from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
Big Sky, MT

Average temperature in January - Big Sky, MT
  • Average high temperature in January: 25°F

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).

  • Average low temperature in January: 9.9°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 in January
Big Sky, MT

Average pressure in January - Big Sky, MT
  • Average pressure in January: 30.22"Hg

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 in January
Big Sky, MT

Average wind speed in January - Big Sky, MT
  • Average wind speed in January: 7.1mph

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 in January
Big Sky, MT

Average humidity in January - Big Sky, MT
  • Average humidity in January: 90%

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

Average rainfall in January
Big Sky, MT

Average rainfall in January - Big Sky, MT
  • Average rainfall in January: 1.54"

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 in January
Big Sky, MT

Average rainfall days in January - Big Sky, MT
  • Average rainfall days in January: 4.8 days

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 in January
Big Sky, MT

Average snowfall in January - Big Sky, MT
  • Average snowfall in January: 12.72"

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

Average snowfall days in January
Big Sky, MT

Average snowfall days in January - Big Sky, MT
  • Average snowfall days in January: 18.9 days

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 in January /
Average sunshine in January
Big Sky, MT

Average daylight in January / Average sunshine in January - Big Sky, MT
  • Average daylight in January: 9h and 1min

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).

  • Average sunshine in January: 4h and 4min

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 in January
Big Sky, MT

Average sunshine days in January - Big Sky, MT
  • Average sunshine days in January: 12.3 days

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 UV index in January
Big Sky, MT

Average UV index in January - Big Sky, MT
  • Average UV index in January: 1

The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January and February (UV index 1).

Average cloud cover in January
Big Sky, MT

Average cloud cover in January - Big Sky, MT
  • Average cloud cover in January: 55

The month with the most cloud cover is February (Cloud cover 60).
The month with the least cloud cover is July (Cloud cover 17).

Average visibility in January
Big Sky, MT

Average visibility in January - Big Sky, MT
  • Average visibility in January: 4mi

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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