December weather forecast
Plains, MT

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Weather in December

The first month of the winter, December, is still a freezing cold month in Plains, Montana, with an average temperature fluctuating between 28.9°F (-1.7°C) and 16.2°F (-8.8°C).

Temperature

During the coldest month, December, temperatures average a high of 28.9°F (-1.7°C) and a low of 16.2°F (-8.8°C).

Humidity

In December, the average relative humidity in Plains is 91%.

Rainfall

In Plains, in December, during 12.2 rainfall days, 2.99" (76mm) of precipitation is typically accumulated. In Plains, during the entire year, the rain falls for 152.1 days and collects up to 22.09" (561mm) of precipitation.

Snowfall

January through May, September through December are months with snowfall. In Plains, during December, snow falls for 20.4 days and regularly aggregates up to 13.35" (339mm) of snow. In Plains, during the entire year, snow falls for 90.2 days and aggregates up to 58.15" (1477mm) of snow.

Daylight

December has the shortest days of the year, with an average of 8h and 30min of daylight.
On the first day of December in Plains, sunrise is at 8:07 am and sunset at 4:50 pm. On the last day of the month, sunrise is at 8:27 am and sunset at 4:58 pm MST.

Sunshine

In Plains, the average sunshine in December is 3.8h.

UV index

January, February, November and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for the ordinary person.
Note: A maximum high UV index of 1 in December translates into the following recommendations:
Despite most people tolerating extended sun exposure, it is critical to always protect those with sensitive skin, infants, and children. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Employ a wide-brim hat for potent defense against up to 50% of UV rays. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the coldest months in Plains?

December is the month when Plains, Montana, sees the average lowest temperatures, with a high of 28.9°F (-1.7°C) and a low of 16.2°F (-8.8°C).

How cold is December in Plains?

An average high-temperature, in December, in Plains, is 28.9°F (-1.7°C) and the average low-temperature is 16.2°F (-8.8°C).

What is the average humidity in December in Plains?

In Plains, Montana, the average relative humidity in December is 91%.

How much does it rain in Plains in December?

In Plains, in December, during 12.2 rainfall days, 2.99" (76mm) of precipitation is typically accumulated.

How many days does it snow in December in Plains?

In Plains, Montana, during December, snow falls for 20.4 days and regularly aggregates up to 13.35" (339mm) of snow.

What is the month with the shortest days in Plains?

The month with the shortest days in Plains is December, with an average of 8h and 30min of daylight.

How many hours of daylight does Plains have in December?

In December, the average day length in Plains, Montana, is 8h and 32min.

What time are sunrise and sunset in December in Plains?

In December, on the first day of the month, sunrise is at 8:07 am and sunset at 4:50 pm. On the last day of the month, in Plains, Montana, sunrise is at 8:27 am and sunset at 4:58 pm MST.

How long on average sun shines in December in Plains?

In Plains, Montana, the average sunshine duration in December is 3.8h.

When is the lowest UV index in Plains?

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

How high is the UV index in December in Plains?

In December, the average daily maximum UV index in Plains is 1. A UV Index estimate of 2, and below, represents a low health threat from exposure to Sun's UV rays.
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 December
Plains, MT

Average temperature in December - Plains, MT
  • Average high temperature in December: 28.9°F

The warmest months (with the highest average high temperature) are July and August (78.8°F).
The month with the lowest average high temperature is December (28.9°F).

  • Average low temperature in December: 16.2°F

The month with the highest average low temperature is August (45.7°F).
The coldest month (with the lowest average low temperature) is December (16.2°F).

Average pressure in December
Plains, MT

Average pressure in December - Plains, MT
  • Average pressure in December: 30.17"Hg

The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
Plains, MT

Average wind speed in December - Plains, MT
  • Average wind speed in December: 4mph

The windiest month (with the highest average wind speed) is April (4.9mph).
The calmest month (with the lowest average wind speed) is December (4mph).

Average humidity in December
Plains, MT

Average humidity in December - Plains, MT
  • Average humidity in December: 91%

The month with the highest relative humidity is January (93%).
The months with the lowest relative humidity are July and August (53%).

Average rainfall in December
Plains, MT

Average rainfall in December - Plains, MT
  • Average rainfall in December: 2.99"

The wettest month (with the highest rainfall) is January (3.11").
The driest month (with the least rainfall) is August (0.39").

Average rainfall days in December
Plains, MT

Average rainfall days in December - Plains, MT
  • Average rainfall days in December: 12.2 days

The month with the highest number of rainy days is March (19.9 days).
The month with the least rainy days is August (5.9 days).

Average snowfall in December
Plains, MT

Average snowfall in December - Plains, MT
  • Average snowfall in December: 13.35"

The month with the highest snowfall is February (15.12").
The months with the least snowfall are June, July and August (0").

Average snowfall days in December
Plains, MT

Average snowfall days in December - Plains, MT
  • Average snowfall days in December: 20.4 days

The month with the highest number of snowfall days is December (20.4 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in December /
Average sunshine in December
Plains, MT

Average daylight in December / Average sunshine in December - Plains, MT
  • Average daylight in December: 8h and 3min

The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).

  • Average sunshine in December: 3h and 5min

The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).

Average sunshine days in December
Plains, MT

Average sunshine days in December - Plains, MT
  • Average sunshine days in December: 8.1 days

The months with the most sunshine days are July and August (23.3 days).
The month with the least sunshine days is March (5.8 days).

Average UV index in December
Plains, MT

Average UV index in December - Plains, MT
  • Average UV index in December: 1

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 1).

Average cloud cover in December
Plains, MT

Average cloud cover in December - Plains, MT
  • Average cloud cover in December: 63

The month with the most cloud cover is February (Cloud cover 66).
The months with the least cloud cover are July and August (Cloud cover 15).

Average visibility in December
Plains, MT

Average visibility in December - Plains, MT
  • Average visibility in December: 3mi

The months with the highest visibility are June, July, August and September (6mi).
The months with the lowest visibility are January, February and December (3mi).

Plains, Montana, USA

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