Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
The coldest period is December, when temperatures fluctuate between an average high of 31.6°F (-0.2°C) and a low of 21.4°F (-5.9°C).Humidity
In December, the average relative humidity is 86%.Rainfall
The months with the most rainfall in Coulee Dam are May and December, with an average 1.18" (30mm) of precipitation.Snowfall
January through April, September through December are months with snowfall in Coulee Dam. In Coulee Dam, in December, snow falls for 10.5 days, with typically accumulated 3.78" (96mm) of snow. Throughout the year, there are 33.4 snowfall days, and 14.65" (372mm) of snow is accumulated.Daylight
December has the shortest days of the year in Coulee Dam, Washington, with an average of 8h and 30min of daylight.On the first day of the month, sunrise is at 7:25 am and sunset at 4:05 pm. On the last day of December, in Coulee Dam, sunrise is at 7:45 am and sunset at 4:13 pm PST.
Sunshine
The average sunshine in December is 4.4h.UV index
The average daily maximum UV index in December is 2. A UV Index reading of 2, and below, represents a low health risk from unsafe exposure to UV radiation for the ordinary person.Note: The UV index of 2 in December translates into these instructions:
Children must always have sun protection, unlike most people, who can tolerate up to an hour in the sun without any burns. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Take note! UV radiation from the Sun can double in intensity due to snow reflection.
Frequently asked questions
What part of the year is the coldest in Coulee Dam?
How cold is December in Coulee Dam?
What is the average humidity in December in Coulee Dam?
What is the rainiest month in Coulee Dam?
How many days does it rain in December in Coulee Dam?
How much does it snow in Coulee Dam in December?
What is the month with the shortest days in Coulee Dam?
How many hours of daylight does Coulee Dam have in December?
What time are sunrise and sunset in December in Coulee Dam?
How long on average sun shines in December in Coulee Dam?
How high is the UV index in December in Coulee Dam?
Average temperature in December
Coulee Dam, WA
- Average high temperature in December: 31.6°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is December (31.6°F).
- Average low temperature in December: 21.4°F
The month with the highest average low temperature is August (61.3°F).
The coldest month (with the lowest average low temperature) is December (21.4°F).
Average pressure in December
Coulee Dam, WA
- Average pressure in December: 30.15"Hg
The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in December
Coulee Dam, WA
- Average wind speed in December: 5mph
The windiest month (with the highest average wind speed) is April (7mph).
The calmest month (with the lowest average wind speed) is January (4.9mph).
Average humidity in December
Coulee Dam, WA
- Average humidity in December: 86%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (36%).
Average rainfall in December
Coulee Dam, WA
- Average rainfall in December: 1.18"
The wettest months (with the highest rainfall) are May and December (1.18").
The driest months (with the least rainfall) are July and August (0.2").
Average rainfall days in December
Coulee Dam, WA
- Average rainfall days in December: 8.5 days
The month with the highest number of rainy days is March (12.1 days).
The month with the least rainy days is August (3.2 days).
Average snowfall in December
Coulee Dam, WA
- Average snowfall in December: 3.78"
The month with the highest snowfall is January (4.41").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in December
Coulee Dam, WA
- Average snowfall days in December: 10.5 days
The month with the highest number of snowfall days is December (10.5 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Coulee Dam, WA
- Average daylight in December: 8h and 3min
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 2min
The month with the most sunshine is August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in December
Coulee Dam, WA
- Average sunshine days in December: 16 days
The month with the most sunshine days is August (25.8 days).
The month with the least sunshine days is March (14.7 days).
Average UV index in December
Coulee Dam, WA
- Average UV index in December: 2
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is November (UV index 1).
Average cloud cover in December
Coulee Dam, WA
- Average cloud cover in December: 52
The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are July and August (Cloud cover 12).
Average visibility in December
Coulee Dam, WA
- Average visibility in December: 4mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (4mi).
Coulee Dam, Washington, USA
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