December weather forecastCedar Mill, OR
December
Weather in December
December, the first month of the winter in Cedar Mill, is still a chilly month, with an average temperature ranging between max 44.2°F (6.8°C) and min 34.7°F (1.5°C).Temperature
December, known for its average high temperature of 44.2°F (6.8°C) and an average low temperature of 34.7°F (1.5°C), is the coldest month.Humidity
February and December, with an average relative humidity of 84%, are the most humid months.Rainfall
The month with the most rainfall is December, when the rain falls for 18.7 days and typically aggregates up to 4.61" (117mm) of precipitation.Snowfall
January through March, November and December are months with snowfall. In December, it is snowing for 0.8 days. Throughout December, 0.43" (11mm) of snow is accumulated. In Cedar Mill, during the entire year, snow falls for 6.1 days and aggregates up to 4.37" (111mm) of snow.Daylight
The month with the shortest days in Cedar Mill is December, with an average of 8h and 48min of daylight.On the first day of December, sunrise is at 7:31 am and sunset at 4:29 pm. On the last day of the month, sunrise is at 7:51 am and sunset at 4:37 pm PST.
Sunshine
In December, the average sunshine is 4.1h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a low threat to health 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:
Apart from children, who require continuous protection, most can endure sun exposure for up to an hour without experiencing burns. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Cedar Mill, OR
- Average high temperature in December: 44.2°F
The warmest month (with the highest average high temperature) is August (81.7°F).
The month with the lowest average high temperature is December (44.2°F).
- Average low temperature in December: 34.7°F
The month with the highest average low temperature is August (55.6°F).
The coldest month (with the lowest average low temperature) is December (34.7°F).
Average pressure in December
Cedar Mill, OR
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).
Average wind speed in December
Cedar Mill, OR
- Average wind speed in December: 5.2mph
The windiest month (with the highest average wind speed) is January (5.4mph).
The calmest month (with the lowest average wind speed) is August (4mph).
Average humidity in December
Cedar Mill, OR
- Average humidity in December: 84%
The months with the highest relative humidity are February and December (84%).
The month with the lowest relative humidity is August (63%).
Average rainfall in December
Cedar Mill, OR
- Average rainfall in December: 4.61"
The wettest month (with the highest rainfall) is December (4.61").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in December
Cedar Mill, OR
- Average rainfall days in December: 18.7 days
The month with the highest number of rainy days is March (20.6 days).
The month with the least rainy days is August (4.6 days).
Average snowfall in December
Cedar Mill, OR
- Average snowfall in December: 0.43"
The month with the highest snowfall is February (1.61").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Cedar Mill, OR
- Average snowfall days in December: 0.8 days
The month with the highest number of snowfall days is February (2.2 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Cedar Mill, OR
- Average daylight in December: 8h and 48min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in December: 4h and 6min
The month with the most sunshine is August (Average sunshine: 10h and 54min).
The month with the least sunshine is February (Average sunshine: 3h and 54min).
Average sunshine days in December
Cedar Mill, OR
- Average sunshine days in December: 10.3 days
The month with the most sunshine days is July (24.9 days).
The month with the least sunshine days is March (8.6 days).
Average UV index in December
Cedar Mill, OR
- 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, November and December (UV index 2).
Average cloud cover in December
Cedar Mill, OR
- Average cloud cover in December: 58
The month with the most cloud cover is February (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 23).
Average visibility in December
Cedar Mill, OR
- Average visibility in December: 5mi
The months with the highest visibility are July, August and September (6mi).
The months with the lowest visibility are January, February, March, April, May, June, October, November and December (5mi).





