Great Falls
Montana, USA
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
Great Falls, MT

A far view from on top of the vast Missouri River of the City of Lights, Great Falls, Montana, a dusk sky, mirror images in the water
A far view from on top of the vast Missouri River of the City of Lights, Great Falls, Montana, a dusk sky, mirror images in the water
The first month of the winter, December, is still a cold month in Great Falls, Montana, with average temperature ranging between min 14.9°F (-9.5°C) and max 34.5°F (1.4°C).

Temperature

The coldest month is December, with an average high-temperature of 34.5°F (1.4°C) and an average low-temperature of 14.9°F (-9.5°C).

Rainfall

In Great Falls, during 7.5 rainfall days, 0.6" (14mm) of precipitation is typically accumulated. Throughout the year, in Great Falls, there are 99.9 rainfall days, and 14.8" (374.8mm) of precipitation is accumulated.

Snowfall

January through June, August through December are months with snowfall.

Daylight

December has the shortest days of the year in Great Falls, with an average of 8.5h of daylight.

Sunshine

With an average of 3.4h of sunshine, December has the least sunshine of the year in Great Falls, Montana.

UV index

Months with the lowest UV index are January, November and December, with an average maximum UV index of 1. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unsafe exposure to the UV radiation for ordinary individuals.
The average daily UV index of 1 in December transform into the following instructions:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

What is the coldest month in Great Falls?

December is the coldest month in Great Falls, with an average high-temperature of 34.5°F (1.4°C) and an average low-temperature of 14.9°F (-9.5°C).

What is the temperature in December in Great Falls?

In Great Falls, Montana, in December, the average high-temperature is 34.5°F (1.4°C), and the average low-temperature is 14.9°F (-9.5°C).

How many days does it rain in December in Great Falls?

In Great Falls, in December, during 7.5 rainfall days, 0.6" (14mm) of precipitation is typically accumulated.

How many days does it snow in December in Great Falls?

In Great Falls, in December, during 7.5 snowfall days, 9.5" (241.3mm) of snow is typically accumulated.

What is the month with the shortest days in Great Falls?

December has the shortest days of the year in Great Falls, with an average of 8.5h of daylight.

How many hours of daylight does Great Falls have in December?

In December, the average length of the day is 8.5h.

What is the month with the least sunshine in Great Falls?

December has the least sunshine of the year in Great Falls, with an average of 3.4h of sunshine.

How long on average sun shines in December in Great Falls?

In Great Falls, the average sunshine in December is 3.4h.

What is the month with the lowest UV index in Great Falls?

Months with the lowest UV index in Great Falls, Montana, are January, November and December, with an average maximum UV index of 1.

How high is the UV index in December in Great Falls?

The average daily maximum UV index in December in Great Falls, Montana, is 1. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unsafe exposure to the Sun's UV rays.
Average temperature in December - Great Falls, MT
  • Average high temperature in December: 34.6°F

The warmest month (with the highest average high temperature) is July (83.4°F).
The month with the lowest average high temperature is December (34.6°F).

  • Average low temperature in December: 14.9°F

The month with the highest average low temperature is July (51.4°F).
Coldest months (with the lowest average low temperature) are January and December (14.9°F).

Average rainfall in December - Great Falls, MT
  • Average rainfall in December: 0.6"

The wettest month (with the highest rainfall) is June (2.5").
Driest months (with the lowest rainfall) are January and February (0.5").

Average rainfall days in December - Great Falls, MT
  • Average rainfall days in December: 7.5 days

Months with the highest number of rainy days are May and June (11.7 days).
The month with the lowest number of rainy days is October (6.6 days).

Average snowfall in December - Great Falls, MT
  • Average snowfall in December: 9.5"

The month with the highest snowfall is March (11.9").
The month with the lowest snowfall is July (0").

Average snowfall days in December - Great Falls, MT
  • Average snowfall days in December: 7.5 days

The month with the highest number of snowfall days is March (7.8 days).
The month with the lowest number of snowfall days is July (0 days).

Average daylight in December / Average sunshine in December - Great Falls, MT
  • Average daylight in December: 8.5h

The month with the longest days is June (Average daylight: 15.9h).
The month with shortest days is December (Average daylight: 8.5h).

  • Average sunshine in December: 3.4h

The month with most sunshine is July (Average sunshine: 12.2h).
The month with least sunshine is December (Average sunshine: 3.4h).

Average UV index in December - Great Falls, MT
  • Average UV index in December: 1

Months with the highest UV index are June and July (UV index 8).
Months with the lowest UV index are January, November and December (UV index 1).