December weather forecastMill Creek, WA
December
Weather in December
December, the first month of the winter in Mill Creek, is also a wintry month, with temperature in the range of an average low of 35.4°F (1.9°C) and an average high of 42.6°F (5.9°C).Temperature
Mill Creek experiences its lowest average temperatures in December, reaching a peak of 42.6°F (5.9°C) and a minimum of 35.4°F (1.9°C).Humidity
The months with the highest humidity are February and December, with an average relative humidity of 84%.Rainfall
The month with the most rainfall is December, when the rain falls for 18.1 days and typically aggregates up to 3.54" (90mm) of precipitation.Snowfall
January through April, November and December are months with snowfall. In Mill Creek, in December, during 3.2 snowfall days, 1.18" (30mm) of snow is typically accumulated. Throughout the year, there are 16.3 snowfall days, and 10.08" (256mm) 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 the month, sunrise is at 7:37 am and sunset at 4:18 pm. On the last day of December, sunrise is at 7:57 am and sunset at 4:26 pm PST.
Sunshine
In Mill Creek, the average sunshine in December is 4.5h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Mill Creek. A UV Index reading of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for the ordinary person.Note: In December, a regular UV index of 2 translates into these guidelines:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Mill Creek, WA
- Average high temperature in December: 42.6°F
The warmest month (with the highest average high temperature) is August (72.7°F).
The month with the lowest average high temperature is December (42.6°F).
- Average low temperature in December: 35.4°F
The month with the highest average low temperature is August (54°F).
The coldest month (with the lowest average low temperature) is December (35.4°F).
Average pressure in December
Mill Creek, WA
- Average pressure in December: 30.08"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are March, August and September (30.01"Hg).
Average wind speed in December
Mill Creek, WA
- Average wind speed in December: 5.7mph
The windiest month (with the highest average wind speed) is November (6.2mph).
The calmest month (with the lowest average wind speed) is August (3.6mph).
Average humidity in December
Mill Creek, WA
- Average humidity in December: 84%
The months with the highest relative humidity are February and December (84%).
The month with the lowest relative humidity is July (72%).
Average rainfall in December
Mill Creek, WA
- Average rainfall in December: 3.54"
The wettest month (with the highest rainfall) is December (3.54").
The driest month (with the least rainfall) is July (0.43").
Average rainfall days in December
Mill Creek, WA
- Average rainfall days in December: 18.1 days
The month with the highest number of rainy days is March (19.8 days).
The month with the least rainy days is August (6.3 days).
Average snowfall in December
Mill Creek, WA
- Average snowfall in December: 1.18"
The month with the highest snowfall is February (4.61").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Mill Creek, WA
- Average snowfall days in December: 3.2 days
The month with the highest number of snowfall days is February (5.2 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Mill Creek, WA
- Average daylight in December: 8h and 30min
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 30min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in December
Mill Creek, WA
- Average sunshine days in December: 10.7 days
The month with the most sunshine days is August (22.6 days).
The month with the least sunshine days is November (9.1 days).
Average UV index in December
Mill Creek, WA
- Average UV index in December: 2
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Mill Creek, WA
- Average cloud cover in December: 54
The month with the most cloud cover is December (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in December
Mill Creek, WA
- Average visibility in December: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
