December weather forecastChallis, ID
December
Weather in December
December serves as the mid-point of the winter season in Challis, with a firm grip of cold weather conditions. Temperature continues to drop, reaching a low of 8.6°F (-13°C) in this month. Challis experiences an increase in snowfall with levels reaching 3.03" (77mm). December also has the year's shortest daylight hours and the most amount of cloud cover. The month, however, has its own charm, with snow-covered landscapes, ideal for winter sports and festivities.Temperature
The month of December, characterized by an average high of 26.1°F (-3.3°C) and a low of 8.6°F (-13°C), is recognized as the coldest.Humidity
The average relative humidity in December is 84%.Rainfall
In Challis, during December, the rain falls for 4.6 days and regularly aggregates up to 0.51" (13mm) of precipitation. In Challis, during the entire year, the rain falls for 75.7 days and collects up to 6.38" (162mm) of precipitation.Snowfall
Months with snowfall are January through June, September through December. In Challis, Idaho, in December, snow falls for 10.1 days, with typically accumulated 3.03" (77mm) of snow. Throughout the year, there are 51.7 snowfall days, and 18.62" (473mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 8h and 54min of daylight.On the first day of the month, sunrise is at 7:54 am and sunset at 4:58 pm. On the last day of December, sunrise is at 8:13 am and sunset at 5:07 pm MST.
Sunshine
In Challis, the average sunshine in December is 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 of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for the average person.Note: The daily high UV index of 2 during December translates into the following recommendations:
Extended time in the sun generally does not harm most, but those with sensitive skin, infants, and children should always be protected. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. Always opt for UVA and UVB-resistant sunglasses on radiant days. Take into account! The reflection from snow can nearly double the Sun's UV radiation intensity.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Challis, ID
- Average high temperature in December: 26.1°F
The warmest month (with the highest average high temperature) is July (76.6°F).
The month with the lowest average high temperature is December (26.1°F).
- Average low temperature in December: 8.6°F
The month with the highest average low temperature is August (47.8°F).
The coldest month (with the lowest average low temperature) is January (8.1°F).
Average pressure in December
Challis, ID
- 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 (29.91"Hg).
Average wind speed in December
Challis, ID
- Average wind speed in December: 5mph
The windiest months (with the highest average wind speed) are June and July (5.7mph).
The calmest month (with the lowest average wind speed) is January (4.8mph).
Average humidity in December
Challis, ID
- Average humidity in December: 84%
The month with the highest relative humidity is February (87%).
The months with the lowest relative humidity are July and August (38%).
Average rainfall in December
Challis, ID
- Average rainfall in December: 0.51"
The wettest month (with the highest rainfall) is June (1.1").
The driest month (with the least rainfall) is July (0.28").
Average rainfall days in December
Challis, ID
- Average rainfall days in December: 4.6 days
The month with the highest number of rainy days is June (10.2 days).
The month with the least rainy days is January (3.8 days).
Average snowfall in December
Challis, ID
- Average snowfall in December: 3.03"
The month with the highest snowfall is February (3.54").
The months with the least snowfall are July and August (0").
Average snowfall days in December
Challis, ID
- Average snowfall days in December: 10.1 days
The month with the highest number of snowfall days is December (10.1 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in December /
Average sunshine in December
Challis, ID
- Average daylight in December: 8h and 54min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in December: 6h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 5h and 48min).
Average sunshine days in December
Challis, ID
- Average sunshine days in December: 19.3 days
The month with the most sunshine days is July (24.1 days).
The months with the least sunshine days are March and April (17.2 days).
Average UV index in December
Challis, ID
- Average UV index in December: 2
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).
Average cloud cover in December
Challis, ID
- Average cloud cover in December: 41
The month with the most cloud cover is February (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 11).
Average visibility in December
Challis, ID
- Average visibility in December: 5mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and February (4mi).





