December weather forecastCopalis Crossing, WA
December
Weather in December
The first month of the winter, December, is also a frosty month in Copalis Crossing, Washington, with an average temperature ranging between min 39.7°F (4.3°C) and max 45.5°F (7.5°C).Temperature
Copalis Crossing's coldest month, December, generally records average temperatures ranging from a high of 45.5°F (7.5°C) to a low of 39.7°F (4.3°C).Humidity
The most humid month is December, with an average relative humidity of 85%.Rainfall
December is the month with the most rainfall. Rain falls for 18.5 days and accumulates 3.35" (85mm) of precipitation.Snowfall
In Copalis Crossing, snow does not fall in April through October and December.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 7:42 am and sunset at 4:28 pm. On the last day of December, in Copalis Crossing, sunrise is at 8:02 am and sunset at 4:36 pm PST.
Sunshine
In Copalis Crossing, the average sunshine in December is 3.6h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: A maximum UV index of 2 in December translates into the following recommendations:
Although the majority can endure up to an hour in the sun without burns, children always require sun protection. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes. Be alert to the fact! The reflection from snow can nearly double the UV radiation of the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Copalis Crossing, WA
- Average high temperature in December: 45.5°F
The warmest month (with the highest average high temperature) is August (65.8°F).
The month with the lowest average high temperature is December (45.5°F).
- Average low temperature in December: 39.7°F
The month with the highest average low temperature is August (54.5°F).
The coldest month (with the lowest average low temperature) is December (39.7°F).
Average pressure in December
Copalis Crossing, WA
- Average pressure in December: 30.04"Hg
The month with the highest atmospheric pressure is July (30.08"Hg).
The month with the lowest atmospheric pressure is March (30"Hg).
Average wind speed in December
Copalis Crossing, WA
- Average wind speed in December: 10.1mph
The windiest month (with the highest average wind speed) is January (10.9mph).
The calmest month (with the lowest average wind speed) is September (7.1mph).
Average humidity in December
Copalis Crossing, WA
- Average humidity in December: 85%
The month with the highest relative humidity is December (85%).
The months with the lowest relative humidity are April, May and June (81%).
Average rainfall in December
Copalis Crossing, WA
- Average rainfall in December: 3.35"
The wettest month (with the highest rainfall) is December (3.35").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in December
Copalis Crossing, WA
- Average rainfall days in December: 18.5 days
The month with the highest number of rainy days is December (18.5 days).
The month with the least rainy days is July (5.6 days).
Average snowfall in December
Copalis Crossing, WA
- Average snowfall in December: 0"
The month with the highest snowfall is February (1.02").
The months with the least snowfall are April, May, June, July, August, September, October and December (0").
Average snowfall days in December
Copalis Crossing, WA
- Average snowfall days in December: 0.3 days
The month with the highest number of snowfall days is February (1.6 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
Copalis Crossing, WA
- 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: 3h and 36min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in December
Copalis Crossing, WA
- Average sunshine days in December: 10.7 days
The month with the most sunshine days is July (23.8 days).
The month with the least sunshine days is December (10.7 days).
Average UV index in December
Copalis Crossing, WA
- Average UV index in December: 2
The months with the highest UV index are May, June, July, August and September (UV index 4).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Copalis Crossing, WA
- Average cloud cover in December: 61
The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in December
Copalis Crossing, WA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, September, October, November and December (6mi).
The month with the lowest visibility is August (5mi).
