December weather forecastChelan, WA
December
Weather in December
December personifies the heart of winter in Chelan, Washington, with frigid temperatures and generous snowfall. Matching January's weather conditions, December's average low temperatures hit a freezing 19°F (-7.2°C). The city gets draped in a white blanket with the highest snowfall of the year, recording 9.06in. Residents prepare for the shortest days of the year, reducing daylight hours to 8.5 hrs. As the year concludes, January brings back a familiar cold and continues the winter season in Chelan, Washington.Temperature
Chelan, Washington, reaches its lowest average temperatures in December, measuring 30.2°F (-1°C) at the peak and 19°F (-7.2°C) at the lowest.Humidity
The average relative humidity in December in Chelan is 88%.Rainfall
December is the month with the most rainfall. Rain falls for 7.5 days and accumulates 1.65" (42mm) of precipitation.Snowfall
Months with snowfall are January through April, September through December. The month with the most snowfall in Chelan is December, when snow falls for 11.9 days and typically aggregates up to 9.06" (230mm) of snow.Daylight
With an average of 8h and 30min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:29 am and sunset at 4:09 pm. On the last day of December, sunrise is at 7:49 am and sunset at 4:17 pm PST.
Sunshine
In Chelan, the average sunshine in December is 4.5h.UV index
January through March, October through December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV rays for average individuals.Note: In December, the maximum UV index of 2 suggests this advice:
Prolonged exposure to sunlight rarely troubles the majority, but constant protection is vital for babies, children, and fair-skinned people. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. During bright days, sunglasses that offer UVA and UVB defense are recommended. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Chelan, WA
- Average high temperature in December: 30.2°F
The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is December (30.2°F).
- Average low temperature in December: 19°F
The month with the highest average low temperature is August (55.8°F).
The coldest months (with the lowest average low temperature) are January and December (19°F).
Average pressure in December
Chelan, WA
- Average pressure in December: 30.14"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is August (29.93"Hg).
Average wind speed in December
Chelan, WA
- Average wind speed in December: 3.5mph
The windiest month (with the highest average wind speed) is June (6.1mph).
The calmest months (with the lowest average wind speed) are January and December (3.5mph).
Average humidity in December
Chelan, WA
- Average humidity in December: 88%
The month with the highest relative humidity is January (90%).
The months with the lowest relative humidity are July and August (43%).
Average rainfall in December
Chelan, WA
- Average rainfall in December: 1.65"
The wettest month (with the highest rainfall) is December (1.65").
The driest month (with the least rainfall) is July (0.16").
Average rainfall days in December
Chelan, WA
- Average rainfall days in December: 7.5 days
The month with the highest number of rainy days is March (12.8 days).
The month with the least rainy days is August (3.8 days).
Average snowfall in December
Chelan, WA
- Average snowfall in December: 9.06"
The month with the highest snowfall is December (9.06").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in December
Chelan, WA
- Average snowfall days in December: 11.9 days
The month with the highest number of snowfall days is January (12 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Chelan, WA
- Average daylight in December: 8h and 30min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in December: 4h and 30min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in December
Chelan, WA
- Average sunshine days in December: 15.2 days
The month with the most sunshine days is July (25.7 days).
The month with the least sunshine days is March (13.2 days).
Average UV index in December
Chelan, WA
- 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, October, November and December (UV index 2).
Average cloud cover in December
Chelan, WA
- Average cloud cover in December: 52
The month with the most cloud cover is January (Cloud cover 54).
The months with the least cloud cover are July and August (Cloud cover 12).
Average visibility in December
Chelan, WA
- Average visibility in December: 4mi
The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February and December (4mi).
