December weather forecastCasper, WY
December
Weather in December
December marks the mid of the cold winter season in Casper, Wyoming, immersing the town in a festive spirit. Suffering the brunt of cold, temperatures plunge dramatically, with average highs dropping to 28.4°F (-2°C) and lows to around 15.1°F (-9.4°C). This month witnesses a considerable amount of snow enveloping the city in a beautiful white landscape. Despite the cold and shorter days, December brings along a charming holiday warmth, making it an invigorating time of the year.Temperature
The month of December sees the lowest average temperatures, reaching 28.4°F (-2°C) at the peak and 15.1°F (-9.4°C) at the low.Humidity
In December, the average relative humidity is 77%.Rainfall
In Casper, Wyoming, in December, during 4.1 rainfall days, 0.51" (13mm) of precipitation is typically accumulated. Throughout the year, there are 91.6 rainfall days, and 9.69" (246mm) of precipitation is accumulated.Snowfall
Months with snowfall in Casper are January through May, September through December. In Casper, during December, snow falls for 9.9 days and regularly aggregates up to 3.7" (94mm) of snow. Throughout the year, in Casper, Wyoming, there are 61.5 snowfall days, and 32.13" (816mm) of snow is accumulated.Daylight
With an average of 9h and 6min of daylight, December has the shortest days of the year in Casper.On the first day of December in Casper, sunrise is at 7:17 am and sunset at 4:32 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 4:41 pm MST.
Sunshine
The average sunshine in December in Casper is 6.4h.UV index
January through April, October through December, with an average maximum UV index of 2, are months with the lowest UV index in Casper. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for the average person.Note: The maximum daily UV index of 2 during December translates into the following directions:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key. Take note! UV radiation from the Sun can double in intensity due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Casper, WY
- Average high temperature in December: 28.4°F
The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is December (28.4°F).
- Average low temperature in December: 15.1°F
The month with the highest average low temperature is July (59.5°F).
The coldest month (with the lowest average low temperature) is December (15.1°F).
Average pressure in December
Casper, WY
- Average pressure in December: 30.15"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in December
Casper, WY
- Average wind speed in December: 11.7mph
The windiest month (with the highest average wind speed) is January (12.1mph).
The calmest months (with the lowest average wind speed) are July and August (8.5mph).
Average humidity in December
Casper, WY
- Average humidity in December: 77%
The month with the highest relative humidity is January (79%).
The month with the lowest relative humidity is August (37%).
Average rainfall in December
Casper, WY
- Average rainfall in December: 0.51"
The wettest month (with the highest rainfall) is May (1.77").
The driest months (with the least rainfall) are January, August and September (0.43").
Average rainfall days in December
Casper, WY
- Average rainfall days in December: 4.1 days
The month with the highest number of rainy days is May (14.1 days).
The month with the least rainy days is January (3.6 days).
Average snowfall in December
Casper, WY
- Average snowfall in December: 3.7"
The month with the highest snowfall is November (5.47").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Casper, WY
- Average snowfall days in December: 9.9 days
The month with the highest number of snowfall days is February (11.2 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Casper, WY
- Average daylight in December: 9h and 6min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in December: 6h and 24min
The months with the most sunshine are July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 6h and 6min).
Average sunshine days in December
Casper, WY
- Average sunshine days in December: 20.5 days
The month with the most sunshine days is December (20.5 days).
The month with the least sunshine days is May (11.9 days).
Average UV index in December
Casper, WY
- Average UV index in December: 2
The months with the highest UV index are June, July and August (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
Casper, WY
- Average cloud cover in December: 32
The month with the most cloud cover is February (Cloud cover 36).
The month with the least cloud cover is August (Cloud cover 13).
Average visibility in December
Casper, WY
- 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).
