December weather forecastLewistown, MT
December
Weather in December
December welcomes winter again in Lewistown with temperatures dropping off to a chilly 29.1°F (-1.6°C), reverting to the weather state from the start of the year. An increased snowfall reaching 4.88" (124mm) and more snowy days mark the full-fledged arrival of winter. A significant dip in daylight and sunshine hours speaks volumes about the winter dominance. With wind speed remaining steady and humidity ascending, December rounds off the year encapsulating the icy spirit of winter.Temperature
Lewistown's temperatures tend to hit their minimum during February and December, with an average high-temperature of 29.1°F (-1.6°C).Humidity
In December, the average relative humidity is 77%.Rainfall
December is the month with the least rainfall. Rain falls for 6 days and accumulates 0.71" (18mm) of precipitation.Snowfall
Months with snowfall are January through June, September through December. In December, it is snowing for 13.5 days. Throughout December, 4.88" (124mm) of snow is accumulated. In Lewistown, during the entire year, snow falls for 83.4 days and aggregates up to 45.51" (1156mm) of snow.Daylight
December has the shortest days of the year, with an average of 8h and 36min of daylight.On the first day of the month, sunrise is at 7:43 am and sunset at 4:30 pm. On the last day of December, sunrise is at 8:03 am and sunset at 4:38 pm MST.
Sunshine
In December, the average sunshine is 5.6h.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 low threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: A maximum high UV index of 2 in December translates into the following recommendations:
Extended sunlight exposure does not pose significant problems for most people, except for children, infants, and people with fair skin who always need shielding. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Lewistown, MT
- Average high temperature in December: 29.1°F
The warmest month (with the highest average high temperature) is July (78.8°F).
The months with the lowest average high temperature are February and December (29.1°F).
- Average low temperature in December: 16°F
The month with the highest average low temperature is August (54.5°F).
The coldest month (with the lowest average low temperature) is February (15.3°F).
Average pressure in December
Lewistown, MT
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in December
Lewistown, MT
- Average wind speed in December: 9.5mph
The windiest months (with the highest average wind speed) are January, April and October (9.9mph).
The calmest month (with the lowest average wind speed) is August (7.4mph).
Average humidity in December
Lewistown, MT
- Average humidity in December: 77%
The month with the highest relative humidity is February (79%).
The month with the lowest relative humidity is August (47%).
Average rainfall in December
Lewistown, MT
- Average rainfall in December: 0.71"
The wettest month (with the highest rainfall) is May (3.39").
The driest month (with the least rainfall) is December (0.71").
Average rainfall days in December
Lewistown, MT
- Average rainfall days in December: 6 days
The month with the highest number of rainy days is May (19.3 days).
The month with the least rainy days is January (5.4 days).
Average snowfall in December
Lewistown, MT
- Average snowfall in December: 4.88"
The month with the highest snowfall is April (9.13").
The months with the least snowfall are July and August (0").
Average snowfall days in December
Lewistown, MT
- Average snowfall days in December: 13.5 days
The month with the highest number of snowfall days is February (15.2 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in December /
Average sunshine in December
Lewistown, MT
- Average daylight in December: 8h and 36min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in December: 5h and 36min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 30min).
Average sunshine days in December
Lewistown, MT
- Average sunshine days in December: 16 days
The month with the most sunshine days is September (19.3 days).
The month with the least sunshine days is April (8.3 days).
Average UV index in December
Lewistown, 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, April, October, November and December (UV index 2).
Average cloud cover in December
Lewistown, MT
- Average cloud cover in December: 41
The month with the most cloud cover is February (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 16).
Average visibility in December
Lewistown, 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).
