December weather forecastRainier, OR
December
Weather in December
December, the first month of the winter in Rainier, is also a wintry month, with an average temperature fluctuating between 42.3°F (5.7°C) and 32.7°F (0.4°C).Temperature
December tends to be the coldest month, with temperatures averaging a daily high of 42.3°F (5.7°C) and a low of 32.7°F (0.4°C).Humidity
January, February, November and December, with an average relative humidity of 88%, are the most humid months.Rainfall
In December, the rain falls for 18.5 days. Throughout December, 3.58" (91mm) of precipitation is accumulated. Throughout the year, there are 175.5 rainfall days, and 25.83" (656mm) of precipitation is accumulated.Snowfall
Months with snowfall in Rainier are January through March, November and December. In December, it is snowing for 0.9 days. Throughout December, 0.24" (6mm) of snow is accumulated. In Rainier, during the entire year, snow falls for 6.7 days and aggregates up to 3.54" (90mm) of snow.Daylight
With an average of 8h and 42min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:34 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:53 am and sunset at 4:36 pm PST.
Sunshine
The months with the least sunshine are January, February and December, with an average of 3.5h of sunshine.UV index
In December, the average daily maximum UV index is 2. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV rays for average individuals.Note: A daily maximum UV index of 2 in December translates into the following instructions:
Most individuals face no major issues with lengthy exposure to the sun, but children, infants, and individuals with fair skin always require protection. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Rainier, OR
- Average high temperature in December: 42.3°F
The warmest month (with the highest average high temperature) is August (77.9°F).
The month with the lowest average high temperature is December (42.3°F).
- Average low temperature in December: 32.7°F
The month with the highest average low temperature is August (49.8°F).
The coldest month (with the lowest average low temperature) is December (32.7°F).
Average pressure in December
Rainier, OR
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).
Average wind speed in December
Rainier, OR
- Average wind speed in December: 4.7mph
The windiest month (with the highest average wind speed) is January (4.8mph).
The calmest month (with the lowest average wind speed) is September (3.9mph).
Average humidity in December
Rainier, OR
- Average humidity in December: 88%
The months with the highest relative humidity are January, February, November and December (88%).
The month with the lowest relative humidity is July (72%).
Average rainfall in December
Rainier, OR
- Average rainfall in December: 3.58"
The wettest month (with the highest rainfall) is January (3.9").
The driest month (with the least rainfall) is August (0.39").
Average rainfall days in December
Rainier, OR
- Average rainfall days in December: 18.5 days
The month with the highest number of rainy days is March (20.3 days).
The month with the least rainy days is July (6.1 days).
Average snowfall in December
Rainier, OR
- Average snowfall in December: 0.24"
The month with the highest snowfall is January (1.26").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Rainier, OR
- Average snowfall days in December: 0.9 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
Rainier, OR
- Average daylight in December: 8h and 42min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in December: 3h and 30min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The months with the least sunshine are January, February and December (Average sunshine: 3h and 30min).
Average sunshine days in December
Rainier, OR
- Average sunshine days in December: 10.2 days
The month with the most sunshine days is July (22 days).
The month with the least sunshine days is March (8.9 days).
Average UV index in December
Rainier, OR
- Average UV index in December: 2
The months with the highest UV index are June and July (UV index 5).
The month with the lowest UV index is November (UV index 1).
Average cloud cover in December
Rainier, OR
- Average cloud cover in December: 64
The months with the most cloud cover are February and March (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 36).
Average visibility in December
Rainier, OR
- Average visibility in December: 4mi
The month with the highest visibility is August (5mi).
The months with the lowest visibility are January, February, March, April, May, June, July, September, October, November and December (4mi).
