December weather forecast
Simms, MT

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Weather in December

The first month of the winter, December, is still a freezing cold month in Simms, Montana, with temperature in the range of an average high of 29.5°F (-1.4°C) and an average low of 17.4°F (-8.1°C).

Temperature

The month of December, characterized by an average high of 29.5°F (-1.4°C) and a low of 17.4°F (-8.1°C), is recognized as the coldest.

Humidity

The average relative humidity in December in Simms is 77%.

Rainfall

In Simms, in December, during 4.9 rainfall days, 0.67" (17mm) of precipitation is typically accumulated. Throughout the year, in Simms, there are 112.8 rainfall days, and 12.95" (329mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through May, September through December. In Simms, during December, snow falls for 12.4 days and regularly aggregates up to 4.37" (111mm) of snow. In Simms, Montana, during the entire year, snow falls for 69.4 days and aggregates up to 35.35" (898mm) of snow.

Daylight

With an average of 8h and 30min of daylight, December has the shortest days of the year.
On the first day of December in Simms, sunrise is at 7:55 am and sunset at 4:38 pm. On the last day of the month, sunrise is at 8:15 am and sunset at 4:46 pm MST.

Sunshine

January and December, with an average of 5.4h of sunshine, are months with the least sunshine.

UV index

The months with the lowest UV index are January through March, October through December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a low threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: The maximum daily UV index, 2 in December, converts into the following recommendations:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. Direct Sun exposure should be minimized especially during midday when radiation is most intense. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest time of year in Simms?

December tends to be the coldest month, with temperatures averaging a daily high of 29.5°F (-1.4°C) and a low of 17.4°F (-8.1°C).

How cold is it in Simms in December?

The high-temperature, in December, in Simms, is 29.5°F (-1.4°C), while the low-temperature averages to 17.4°F (-8.1°C). The average heat index (a.k.a. 'felt air temperature', 'feels like'), which combines relative humidity and air temperature, in August is appraised at 80.6°F (27°C).

What is the average humidity in December in Simms?

In Simms, Montana, the average relative humidity in December is 77%.

How much does it rain in Simms in December?

In Simms, Montana, during December, the rain falls for 4.9 days and regularly aggregates up to 0.67" (17mm) of precipitation.

How much does it snow in Simms in December?

In December, in Simms, Montana, it is snowing for 12.4 days. Throughout December, 4.37" (111mm) of snow is accumulated.

What is the month with the shortest days in Simms?

December has the shortest days of the year in Simms, Montana, with an average of 8h and 30min of daylight.

What is the average length of the day in December in Simms?

The average day length in December is 8h and 31min.

When is the sunrise / sunset in December in Simms?

In December, on the first day of the month, sunrise is at 7:55 am and sunset at 4:38 pm. On the last day of the month, sunrise is at 8:15 am and sunset at 4:46 pm MST.

What is the month with the least sunshine in Simms?

The months with the least sunshine are January and December, with an average of 5.4h of sunshine.

How long on average sun shines in December in Simms?

In Simms, Montana, the average sunshine duration in December is 5.4h.

What are the months with the lowest UV index in Simms?

The months with the lowest UV index in Simms are January through March, October through December, with an average maximum UV index of 2.

What is the UV index reading in December in Simms?

The average daily maximum UV index in December is 2. A UV Index estimate of 2, and below, represents a minimal hazard to health from unsafe 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
Simms, MT

Average temperature in December - Simms, MT
  • Average high temperature in December: 29.5°F

The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is December (29.5°F).

  • Average low temperature in December: 17.4°F

The month with the highest average low temperature is August (56.7°F).
The coldest month (with the lowest average low temperature) is December (17.4°F).

Average pressure in December
Simms, MT

Average pressure in December - Simms, MT
  • Average pressure in December: 30.14"Hg

The months with the highest atmospheric pressure are January and December (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).

Average wind speed in December
Simms, MT

Average wind speed in December - Simms, MT
  • Average wind speed in December: 10.4mph

The windiest months (with the highest average wind speed) are January and November (10.7mph).
The calmest month (with the lowest average wind speed) is August (7.3mph).

Average humidity in December
Simms, MT

Average humidity in December - Simms, MT
  • Average humidity in December: 77%

The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is August (41%).

Average rainfall in December
Simms, MT

Average rainfall in December - Simms, MT
  • Average rainfall in December: 0.67"

The wettest month (with the highest rainfall) is June (2.05").
The driest months (with the least rainfall) are January and July (0.63").

Average rainfall days in December
Simms, MT

Average rainfall days in December - Simms, MT
  • Average rainfall days in December: 4.9 days

The month with the highest number of rainy days is May (15.2 days).
The month with the least rainy days is January (4.8 days).

Average snowfall in December
Simms, MT

Average snowfall in December - Simms, MT
  • Average snowfall in December: 4.37"

The month with the highest snowfall is February (6.34").
The months with the least snowfall are June, July and August (0").

Average snowfall days in December
Simms, MT

Average snowfall days in December - Simms, MT
  • Average snowfall days in December: 12.4 days

The month with the highest number of snowfall days is February (14.4 days).
The months with the least snowfall days are July and August (0 days).

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

Average daylight in December / Average sunshine in December - Simms, 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: 5h and 2min

The month with the most sunshine is July (Average sunshine: 11h and 54min).
The months with the least sunshine are January and December (Average sunshine: 5h and 24min).

Average sunshine days in December
Simms, MT

Average sunshine days in December - Simms, MT
  • Average sunshine days in December: 17.7 days

The month with the most sunshine days is September (18.8 days).
The month with the least sunshine days is April (10.3 days).

Average UV index in December
Simms, MT

Average UV index in December - Simms, MT
  • Average UV index in December: 2

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).

Average cloud cover in December
Simms, MT

Average cloud cover in December - Simms, MT
  • Average cloud cover in December: 43

The month with the most cloud cover is February (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 14).

Average visibility in December
Simms, MT

Average visibility in December - Simms, MT
  • Average visibility in December: 6mi

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

Simms, Montana, USA

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