December weather forecast
Grantsville, UT

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Weather in December

December, the first month of the winter in Grantsville, is also an icy month, with temperature in the range of an average low of 22.1°F (-5.5°C) and an average high of 33.8°F (1°C).

Temperature

December brings a decrease in the average high-temperature, shifting from a chilly 45.9°F (7.7°C) in November to a wintry 33.8°F (1°C). Throughout December, Grantsville's nights cool down to an average of 22.1°F (-5.5°C).

Humidity

The average relative humidity in December is 78%.

Rainfall

In Grantsville, in December, during 10.6 rainfall days, 1.93" (49mm) of precipitation is typically accumulated. In Grantsville, during the entire year, the rain falls for 137.7 days and collects up to 20.98" (533mm) of precipitation.

Snowfall

January through May, October through December are months with snowfall. The month with the most snowfall is December, when snow falls for 12.5 days and typically aggregates up to 9.69" (246mm) of snow.

Daylight

December has the shortest days of the year, with an average of 9h and 18min of daylight.
On the first day of December, sunrise is at 7:34 am and sunset at 5:03 pm. On the last day of the month, sunrise is at 7:53 am and sunset at 5:13 pm MST.

Sunshine

In December, the average sunshine is 5.4h.

UV index

The month with the lowest UV index is December, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a minimal health vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In December, a regular UV index of 1 translates into these guidelines:
Many can withstand an hour in the sun without burning, yet children must always have protection against sunlight. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. Be cautious! The UV radiation from the Sun can be magnified almost twofold by snow reflection.
Updated: Aug 22, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in December?

Grantsville in December has an average high-temperature of 33.8°F (1°C) and an average low-temperature of 22.1°F (-5.5°C).

What is the average humidity in December?

The average relative humidity in December is 78%.

How many days does it rain in December?

In Grantsville, during December, the rain falls for 10.6 days and regularly aggregates up to 1.93" (49mm) of precipitation.

What is the snowiest month?

December is the month with the most snowfall. Snow falls for 12.5 days and accumulates 9.69" (246mm) of snow.

How much does it snow in December?

In Grantsville, in December, during 12.5 snowfall days, 9.69" (246mm) of snow is typically accumulated.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 18min of daylight.

How many hours of daylight does Grantsville have in December?

In Grantsville, the average day length in December is 9h and 20min.

What time are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:34 am and sunset at 5:03 pm. On the last day of the month, sunrise is at 7:53 am and sunset at 5:13 pm MST.

How long on average sun shines in December?

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

When is the lowest UV index?

With an average maximum UV index of 1, December is the month with the lowest UV index.

How high is the UV index in December?

The average daily maximum UV index in December 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 December
Grantsville, UT

Average temperature in December - Grantsville, UT
  • Average high temperature in December: 33.8°F

The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (33.4°F).

  • Average low temperature in December: 22.1°F

The month with the highest average low temperature is July (63.5°F).
The coldest month (with the lowest average low temperature) is January (21.2°F).

Average pressure in December
Grantsville, UT

Average pressure in December - Grantsville, UT
  • Average pressure in December: 30.22"Hg

The month with the highest atmospheric pressure is January (30.27"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).

Average wind speed in December
Grantsville, UT

Average wind speed in December - Grantsville, UT
  • Average wind speed in December: 7.1mph

The windiest month (with the highest average wind speed) is March (8.1mph).
The calmest month (with the lowest average wind speed) is January (6mph).

Average humidity in December
Grantsville, UT

Average humidity in December - Grantsville, UT
  • Average humidity in December: 78%

The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is July (36%).

Average rainfall in December
Grantsville, UT

Average rainfall in December - Grantsville, UT
  • Average rainfall in December: 1.93"

The wettest month (with the highest rainfall) is April (2.52").
The driest month (with the least rainfall) is June (1.1").

Average rainfall days in December
Grantsville, UT

Average rainfall days in December - Grantsville, UT
  • Average rainfall days in December: 10.6 days

The month with the highest number of rainy days is April (16.3 days).
The month with the least rainy days is November (7.5 days).

Average snowfall in December
Grantsville, UT

Average snowfall in December - Grantsville, UT
  • Average snowfall in December: 9.69"

The month with the highest snowfall is December (9.69").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Grantsville, UT

Average snowfall days in December - Grantsville, UT
  • Average snowfall days in December: 12.5 days

The month with the highest number of snowfall days is December (12.5 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Grantsville, UT

Average daylight in December / Average sunshine in December - Grantsville, UT
  • Average daylight in December: 9h and 2min

The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in December: 5h and 2min

The month with the most sunshine is August (Average sunshine: 11h and 48min).
The month with the least sunshine is January (Average sunshine: 5h and 6min).

Average sunshine days in December
Grantsville, UT

Average sunshine days in December - Grantsville, UT
  • Average sunshine days in December: 13.1 days

The month with the most sunshine days is October (19.5 days).
The month with the least sunshine days is February (10.2 days).

Average UV index in December
Grantsville, UT

Average UV index in December - Grantsville, UT
  • Average UV index in December: 1

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

Average cloud cover in December
Grantsville, UT

Average cloud cover in December - Grantsville, UT
  • Average cloud cover in December: 43

The month with the most cloud cover is January (Cloud cover 45).
The month with the least cloud cover is August (Cloud cover 13).

Average visibility in December
Grantsville, UT

Average visibility in December - Grantsville, UT
  • Average visibility in December: 6mi

The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).

Grantsville, Utah, USA

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