December weather forecast
Alta, WY

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Weather in December

The first month of the winter, December, is still a freezing cold month in Alta, Wyoming, with an average temperature fluctuating between 7.7°F (-13.5°C) and 23.2°F (-4.9°C).

Temperature

December, recording an average high temperature of 23.2°F (-4.9°C) and a low temperature of 7.7°F (-13.5°C), is Alta's coldest month.

Humidity

The average relative humidity in December is 91%.

Rainfall

In Alta, in December, during 4.5 rainfall days, 3.15" (80mm) of precipitation is typically accumulated. Throughout the year, in Alta, there are 96.6 rainfall days, and 32.95" (837mm) of precipitation is accumulated.

Snowfall

January through June, August through December are months with snowfall. In Alta, in December, snow falls for 22.8 days, with typically accumulated 25.87" (657mm) of snow. In Alta, during the entire year, snow falls for 160.8 days and aggregates up to 200.16" (5084mm) of snow.

Daylight

With an average of 9h and 0min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 7:38 am and sunset at 4:48 pm. On the last day of December, sunrise is at 7:57 am and sunset at 4:57 pm MST.

Sunshine

In Alta, the average sunshine in December is 3.6h.

UV index

The months with the lowest UV index are January through March, October through December, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for average individuals.
Note: In December, the maximum UV index of 1 suggests these recommendations:
While most individuals can withstand prolonged sun exposure, it is imperative that babies, children, and those with sensitive skin always be shielded. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Updated: Jul 24, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest time of year?

Alta witnesses the coldest weather in December, with temperatures averaging a high of 23.2°F (-4.9°C) and a low of 7.7°F (-13.5°C).

How cold is it in December?

The high-temperature during December is 23.2°F (-4.9°C) and the low-temperature is 7.7°F (-13.5°C).

What is the average humidity in December?

The average relative humidity in December is 91%.

How many days does it rain in December?

In Alta, during December, the rain falls for 4.5 days and regularly aggregates up to 3.15" (80mm) of precipitation.

How much does it snow in December?

In Alta, Wyoming, in December, snow falls for 22.8 days, with typically accumulated 25.87" (657mm) of snow.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 9h and 0min of daylight.

What is the average length of the day in December?

The average day length in December in Alta, Wyoming, is 8h and 59min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:38 am and sunset at 4:48 pm. On the last day of the month, sunrise is at 7:57 am and sunset at 4:57 pm MST.

How long on average sun shines in December?

In December, the average sunshine duration is 3.6h.

What are the months with the lowest UV index?

The months with the lowest UV index are January through March, October through December, with an average maximum UV index of 1.

What is the UV index reading in December?

In December, the average daily maximum UV index is 1. A UV Index of 2, and less, symbolizes a minimal health vulnerability 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
Alta, WY

Average temperature in December - Alta, WY
  • Average high temperature in December: 23.2°F

The warmest month (with the highest average high temperature) is July (75.4°F).
The month with the lowest average high temperature is December (23.2°F).

  • Average low temperature in December: 7.7°F

The month with the highest average low temperature is July (46.9°F).
The coldest month (with the lowest average low temperature) is December (7.7°F).

Average pressure in December
Alta, WY

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

The month with the highest atmospheric pressure is January (30.27"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in December
Alta, WY

Average wind speed in December - Alta, WY
  • Average wind speed in December: 4.8mph

The windiest month (with the highest average wind speed) is June (6.2mph).
The calmest months (with the lowest average wind speed) are January and December (4.8mph).

Average humidity in December
Alta, WY

Average humidity in December - Alta, WY
  • Average humidity in December: 91%

The month with the highest relative humidity is February (94%).
The month with the lowest relative humidity is August (47%).

Average rainfall in December
Alta, WY

Average rainfall in December - Alta, WY
  • Average rainfall in December: 3.15"

The wettest month (with the highest rainfall) is February (4.13").
The driest month (with the least rainfall) is July (0.91").

Average rainfall days in December
Alta, WY

Average rainfall days in December - Alta, WY
  • Average rainfall days in December: 4.5 days

The month with the highest number of rainy days is May (15.5 days).
The month with the least rainy days is January (3 days).

Average snowfall in December
Alta, WY

Average snowfall in December - Alta, WY
  • Average snowfall in December: 25.87"

The month with the highest snowfall is February (34.33").
The month with the least snowfall is July (0").

Average snowfall days in December
Alta, WY

Average snowfall days in December - Alta, WY
  • Average snowfall days in December: 22.8 days

The month with the highest number of snowfall days is March (23.6 days).
The month with the least snowfall days is July (0.1 days).

Average daylight in December /
Average sunshine in December
Alta, WY

Average daylight in December / Average sunshine in December - Alta, WY
  • Average daylight in December: 9h and 0min

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).

  • Average sunshine in December: 3h and 4min

The month with the most sunshine is July (Average sunshine: 11h and 42min).
The month with the least sunshine is February (Average sunshine: 3h and 18min).

Average sunshine days in December
Alta, WY

Average sunshine days in December - Alta, WY
  • Average sunshine days in December: 8.4 days

The month with the most sunshine days is July (20.3 days).
The month with the least sunshine days is April (6.2 days).

Average UV index in December
Alta, WY

Average UV index in December - Alta, WY
  • Average UV index in December: 1

The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, March, October, November and December (UV index 1).

Average cloud cover in December
Alta, WY

Average cloud cover in December - Alta, WY
  • Average cloud cover in December: 67

The month with the most cloud cover is February (Cloud cover 73).
The month with the least cloud cover is August (Cloud cover 14).

Average visibility in December
Alta, WY

Average visibility in December - Alta, WY
  • Average visibility in December: 3mi

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

Alta, Wyoming, USA

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