December weather forecastUmtanum, WA
December
Weather in December
The first month of the winter, December, is also a wintry month in Umtanum, Washington, with an average temperature ranging between min 21.4°F (-5.9°C) and max 33.3°F (0.7°C).Temperature
December, marked by an average high-temperature of 33.3°F (0.7°C) and a low-temperature of 21.4°F (-5.9°C), is the coldest month.Humidity
In Umtanum, the average relative humidity in December is 85%.Rainfall
The month with the most rainfall in Umtanum is December, when the rain falls for 9.4 days and typically aggregates up to 1.3" (33mm) of precipitation.Snowfall
January through April, September through December are months with snowfall in Umtanum. The month with the most snowfall in Umtanum is December, when snow falls for 8.7 days and typically aggregates up to 4.65" (118mm) of snow.Daylight
With an average of 8h and 36min of daylight, December has the shortest days of the year.On the first day of December in Umtanum, sunrise is at 7:27 am and sunset at 4:15 pm. On the last day of the month, sunrise is at 7:47 am and sunset at 4:23 pm PST.
Sunshine
The months with the least sunshine in Umtanum, Washington, are January and December, with an average of 4.8h of sunshine.UV index
January through March, 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 minimal health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The maximum daily UV index of 2 during December translates into the following directions:
Despite most people tolerating extended sun exposure, it is critical to always protect those with sensitive skin, infants, and children. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Mind you! Snow reflection can increase the intensity of the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Umtanum, WA
- Average high temperature in December: 33.3°F
The warmest months (with the highest average high temperature) are July and August (82°F).
The month with the lowest average high temperature is December (33.3°F).
- Average low temperature in December: 21.4°F
The month with the highest average low temperature is August (55.2°F).
The coldest month (with the lowest average low temperature) is December (21.4°F).
Average pressure in December
Umtanum, WA
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is August (29.94"Hg).
Average wind speed in December
Umtanum, WA
- Average wind speed in December: 4.2mph
The windiest month (with the highest average wind speed) is June (8.9mph).
The calmest month (with the lowest average wind speed) is December (4.2mph).
Average humidity in December
Umtanum, WA
- Average humidity in December: 85%
The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are July and August (46%).
Average rainfall in December
Umtanum, WA
- Average rainfall in December: 1.3"
The wettest month (with the highest rainfall) is December (1.3").
The driest month (with the least rainfall) is July (0.16").
Average rainfall days in December
Umtanum, WA
- Average rainfall days in December: 9.4 days
The month with the highest number of rainy days is March (12.4 days).
The month with the least rainy days is August (2.8 days).
Average snowfall in December
Umtanum, WA
- Average snowfall in December: 4.65"
The month with the highest snowfall is December (4.65").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in December
Umtanum, WA
- Average snowfall days in December: 8.7 days
The months with the highest number of snowfall days are January and December (8.7 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Umtanum, 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: 4h and 48min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are January and December (Average sunshine: 4h and 48min).
Average sunshine days in December
Umtanum, WA
- Average sunshine days in December: 15.3 days
The month with the most sunshine days is July (27.1 days).
The month with the least sunshine days is February (13.5 days).
Average UV index in December
Umtanum, 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, November and December (UV index 2).
Average cloud cover in December
Umtanum, WA
- Average cloud cover in December: 47
The month with the most cloud cover is January (Cloud cover 48).
The months with the least cloud cover are July and August (Cloud cover 11).
Average visibility in December
Umtanum, 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).
