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
December is the coldest month, exhibiting average temperatures of 32°F (0°C) at the peak and 21.9°F (-5.6°C) at the base.Humidity
In December, the average relative humidity is 88%.Rainfall
In December, the rain falls for 8.9 days. Throughout December, 2.2" (56mm) of precipitation is accumulated. Throughout the year, there are 125.4 rainfall days, and 17.28" (439mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, September through December. In Millwood, in December, snow falls for 13.9 days, with typically accumulated 8.9" (226mm) of snow. Throughout the year, there are 56.4 snowfall days, and 37.4" (950mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 8h and 30min of daylight.On the first day of December, sunrise is at 7:17 am and sunset at 3:59 pm. On the last day of the month, sunrise is at 7:37 am and sunset at 4:07 pm PST.
Sunshine
January and December, with an average of 3.8h of sunshine, are months with the least sunshine in Millwood.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a minimal health hazard from unsafe exposure to UV radiation for ordinary individuals.Note: In December, the average maximum UV index of 1 translates into the following recommendations:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key. Bear in mind! The Sun's UV radiation can nearly double in intensity due to the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the coldest time of year?
How cold is December?
What is the average humidity in December?
How much does it rain in December?
How many days does it snow in December?
What is the month with the shortest days in Millwood?
How many hours of daylight does Millwood have in December?
When are sunrise and sunset in December?
What are the months with the least sunshine in Millwood?
How long on average sun shines in December?
What is the month with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Millwood, WA
- Average high temperature in December: 32°F
The warmest month (with the highest average high temperature) is August (83.3°F).
The month with the lowest average high temperature is December (32°F).
- Average low temperature in December: 21.9°F
The month with the highest average low temperature is August (55.9°F).
The coldest month (with the lowest average low temperature) is December (21.9°F).
Average pressure in December
Millwood, WA
- Average pressure in December: 30.17"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in December
Millwood, WA
- Average wind speed in December: 4.7mph
The windiest month (with the highest average wind speed) is April (6.1mph).
The calmest month (with the lowest average wind speed) is December (4.7mph).
Average humidity in December
Millwood, WA
- Average humidity in December: 88%
The month with the highest relative humidity is January (91%).
The month with the lowest relative humidity is August (43%).
Average rainfall in December
Millwood, WA
- Average rainfall in December: 2.2"
The wettest month (with the highest rainfall) is January (2.28").
The driest months (with the least rainfall) are July and August (0.35").
Average rainfall days in December
Millwood, WA
- Average rainfall days in December: 8.9 days
The month with the highest number of rainy days is March (16 days).
The month with the least rainy days is July (5.1 days).
Average snowfall in December
Millwood, WA
- Average snowfall in December: 8.9"
The month with the highest snowfall is January (10.51").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Millwood, WA
- Average snowfall days in December: 13.9 days
The month with the highest number of snowfall days is December (13.9 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Millwood, WA
- Average daylight in December: 8h and 3min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in December: 3h and 5min
The month with the most sunshine is August (Average sunshine: 12h and 0min).
The months with the least sunshine are January and December (Average sunshine: 3h and 48min).
Average sunshine days in December
Millwood, WA
- Average sunshine days in December: 13.4 days
The month with the most sunshine days is July (24.3 days).
The month with the least sunshine days is March (10.3 days).
Average UV index in December
Millwood, WA
- Average UV index in December: 1
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Millwood, WA
- Average cloud cover in December: 61
The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are July and August (Cloud cover 13).
Average visibility in December
Millwood, WA
- Average visibility in December: 4mi
The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February and December (4mi).
Millwood, Washington, USA
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