December weather forecast
Rock Springs, WY

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Weather in December

A full-fledged winter arrives in December in Rock Springs with the lowest temperatures ranging from 25.7°F (-3.5°C) to 11.5°F (-11.4°C). The city experiences the highest snowfall of the year, 4.37" (111mm), transforming it into a snowy paradise. The twinkling holiday lights against snowy backgrounds create a festive atmosphere throughout the city. Amidst the blustering cold, the warmth of the holiday season fills the air. It is a time for hot chocolates, cozy fireplaces, and the joy of winter festivities.

Temperature

The lowest temperatures in Rock Springs are recorded in December, with averages reaching a high of 25.7°F (-3.5°C) and a low of 11.5°F (-11.4°C).

Humidity

In December, the average relative humidity in Rock Springs is 82%.

Rainfall

In Rock Springs, in December, it is raining for 4.7 days, with typically 0.71" (18mm) of accumulated precipitation. In Rock Springs, during the entire year, the rain falls for 93.5 days and collects up to 10.31" (262mm) of precipitation.

Snowfall

January through June, September through December are months with snowfall. In December, in Rock Springs, it is snowing for 13.5 days. Throughout December, 4.37" (111mm) of snow is accumulated. Throughout the year, there are 75.5 snowfall days, and 30.16" (766mm) of snow is accumulated.

Daylight

The month with the shortest days in Rock Springs is December, with an average of 9h and 12min of daylight.
On the first day of December in Rock Springs, sunrise is at 7:24 am and sunset at 4:47 pm. On the last day of the month, sunrise is at 7:43 am and sunset at 4:56 pm MST.

Sunshine

The months with the least sunshine in Rock Springs are January and December, with an average of 5.9h of sunshine.

UV index

The months with the lowest UV index are January through April, October through December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV rays for the ordinary person.
Note: An average maximum UV index of 2 in December leads to these recommendations:
Children necessitate constant protection from sunlight, unlike the majority, who can remain under the sun for about an hour without burning. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. To cut down UV radiation exposure by about half, sport a wide-brim hat. Be prepared! The intensity of the Sun's UV radiation can be amplified nearly double due to snow reflection.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest time of year in Rock Springs?

The coldest period in Rock Springs, Wyoming, is December, when temperatures fluctuate between an average high of 25.7°F (-3.5°C) and a low of 11.5°F (-11.4°C).

How cold is it in Rock Springs in December?

An average high-temperature, in December, in Rock Springs, is 25.7°F (-3.5°C) and the average low-temperature is 11.5°F (-11.4°C).

What is the average humidity in December in Rock Springs?

The average relative humidity in December is 82%.

How much does it rain in Rock Springs in December?

In Rock Springs, during December, the rain falls for 4.7 days and regularly aggregates up to 0.71" (18mm) of precipitation.

How much does it snow in Rock Springs in December?

In Rock Springs, Wyoming, in December, during 13.5 snowfall days, 4.37" (111mm) of snow is typically accumulated.

What is the month with the shortest days in Rock Springs?

With an average of 9h and 12min of daylight, December has the shortest days of the year in Rock Springs, Wyoming.

What is the average length of the day in December in Rock Springs?

The average day length in December in Rock Springs is 9h and 13min.

What time are sunrise and sunset in December in Rock Springs?

In December, on the first day of the month, sunrise is at 7:24 am and sunset at 4:47 pm. On the last day of the month, sunrise is at 7:43 am and sunset at 4:56 pm MST.

What is the month with the least sunshine in Rock Springs?

January and December, with an average of 5.9h of sunshine, are months with the least sunshine in Rock Springs, Wyoming.

How long on average sun shines in December in Rock Springs?

In Rock Springs, the average sunshine duration in December is 5.9h.

When is the lowest UV index in Rock Springs?

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

How high is the UV index in December in Rock Springs?

The average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a low health risk 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
Rock Springs, WY

Average temperature in December - Rock Springs, WY
  • Average high temperature in December: 25.7°F

The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is December (25.7°F).

  • Average low temperature in December: 11.5°F

The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is January (10.8°F).

Average pressure in December
Rock Springs, WY

Average pressure in December - Rock Springs, WY
  • Average pressure in December: 30.24"Hg

The month with the highest atmospheric pressure is January (30.28"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

Average wind speed in December
Rock Springs, WY

Average wind speed in December - Rock Springs, WY
  • Average wind speed in December: 9.3mph

The windiest month (with the highest average wind speed) is April (12.2mph).
The calmest month (with the lowest average wind speed) is August (8.7mph).

Average humidity in December
Rock Springs, WY

Average humidity in December - Rock Springs, WY
  • Average humidity in December: 82%

The month with the highest relative humidity is January (84%).
The months with the lowest relative humidity are July and August (31%).

Average rainfall in December
Rock Springs, WY

Average rainfall in December - Rock Springs, WY
  • Average rainfall in December: 0.71"

The wettest month (with the highest rainfall) is May (1.5").
The driest month (with the least rainfall) is July (0.47").

Average rainfall days in December
Rock Springs, WY

Average rainfall days in December - Rock Springs, WY
  • Average rainfall days in December: 4.7 days

The month with the highest number of rainy days is May (13.8 days).
The month with the least rainy days is December (4.7 days).

Average snowfall in December
Rock Springs, WY

Average snowfall in December - Rock Springs, WY
  • Average snowfall in December: 4.37"

The month with the highest snowfall is March (6.14").
The months with the least snowfall are July and August (0").

Average snowfall days in December
Rock Springs, WY

Average snowfall days in December - Rock Springs, WY
  • Average snowfall days in December: 13.5 days

The month with the highest number of snowfall days is December (13.5 days).
The months with the least snowfall days are July and August (0 days).

Average daylight in December /
Average sunshine in December
Rock Springs, WY

Average daylight in December / Average sunshine in December - Rock Springs, WY
  • Average daylight in December: 9h and 1min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in December: 5h and 5min

The months with the most sunshine are July and August (Average sunshine: 11h and 48min).
The months with the least sunshine are January and December (Average sunshine: 5h and 54min).

Average sunshine days in December
Rock Springs, WY

Average sunshine days in December - Rock Springs, WY
  • Average sunshine days in December: 16.4 days

The month with the most sunshine days is September (19.8 days).
The month with the least sunshine days is April (11.5 days).

Average UV index in December
Rock Springs, WY

Average UV index in December - Rock Springs, WY
  • 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, April, October, November and December (UV index 2).

Average cloud cover in December
Rock Springs, WY

Average cloud cover in December - Rock Springs, WY
  • Average cloud cover in December: 41

The month with the most cloud cover is February (Cloud cover 43).
The month with the least cloud cover is August (Cloud cover 13).

Average visibility in December
Rock Springs, WY

Average visibility in December - Rock Springs, WY
  • Average visibility in December: 5mi

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

Rock Springs, Wyoming, USA

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