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, having an average high-temperature of 45.7°F (7.6°C) and an average low-temperature of 32.2°F (0.1°C), is the coldest month.Humidity
January, February and December, with an average relative humidity of 86%, are the most humid months.Rainfall
The wettest months in Tri-City are January, February and December, with an average 1.1" (28mm) of rainfall.Snowfall
January through March, November and December are months with snowfall in Tri-City. In December, it is snowing for 0.5 days. Throughout December, 0.31" (8mm) of snow is accumulated. In Tri-City, during the entire year, snow falls for 3.5 days and aggregates up to 2.2" (56mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 6min of daylight.On the first day of the month, sunrise is at 7:25 am and sunset at 4:39 pm. On the last day of December, in Tri-City, Oregon, sunrise is at 7:44 am and sunset at 4:48 pm PST.
Sunshine
The month with the least sunshine is December, with an average of 4.3h of sunshine.UV index
The months with the lowest UV index in Tri-City are January, February, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: The UV index of 2 in December translates into these instructions:
Though the majority can handle prolonged sun exposure, it is crucial to always shield babies, children, and those with fair skin. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. To cut down UV radiation exposure by about half, sport a wide-brim hat. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Frequently asked questions
What part of the year is the coldest in Tri-City?
What is the average December temperature in Tri-City?
What are the most humid months in Tri-City?
What is the average humidity in December in Tri-City?
What is the rainiest month in Tri-City?
How much does it rain in Tri-City in December?
How much does it snow in Tri-City in December?
What is the month with the shortest days in Tri-City?
What is the average length of the day in December in Tri-City?
When are sunrise and sunset in December in Tri-City?
What is the month with the least sunshine in Tri-City?
How long on average sun shines in December in Tri-City?
What are the months with the lowest UV index in Tri-City?
What is the UV index reading in December in Tri-City?
Average temperature in December
Tri-City, OR
- Average high temperature in December: 45.7°F
The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (45.7°F).
- Average low temperature in December: 32.2°F
The month with the highest average low temperature is August (47.7°F).
The coldest month (with the lowest average low temperature) is December (32.2°F).
Average pressure in December
Tri-City, OR
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in December
Tri-City, OR
- Average wind speed in December: 3.9mph
The windiest month (with the highest average wind speed) is January (4.1mph).
The calmest month (with the lowest average wind speed) is September (3.2mph).
Average humidity in December
Tri-City, OR
- Average humidity in December: 86%
The months with the highest relative humidity are January, February and December (86%).
The month with the lowest relative humidity is August (69%).
Average rainfall in December
Tri-City, OR
- Average rainfall in December: 1.1"
The wettest months (with the highest rainfall) are January, February and December (1.1").
The driest months (with the least rainfall) are July and August (0.16").
Average rainfall days in December
Tri-City, OR
- Average rainfall days in December: 11.4 days
The month with the highest number of rainy days is March (12.6 days).
The month with the least rainy days is August (2.4 days).
Average snowfall in December
Tri-City, OR
- Average snowfall in December: 0.31"
The month with the highest snowfall is February (0.87").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Tri-City, OR
- Average snowfall days in December: 0.5 days
The month with the highest number of snowfall days is February (1.5 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
Tri-City, OR
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in December: 4h and 2min
The month with the most sunshine is August (Average sunshine: 11h and 18min).
The month with the least sunshine is December (Average sunshine: 4h and 18min).
Average sunshine days in December
Tri-City, OR
- Average sunshine days in December: 17.7 days
The month with the most sunshine days is August (26.5 days).
The month with the least sunshine days is March (16.1 days).
Average UV index in December
Tri-City, OR
- 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, November and December (UV index 2).
Average cloud cover in December
Tri-City, OR
- Average cloud cover in December: 56
The month with the most cloud cover is March (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in December
Tri-City, OR
- Average visibility in December: 4mi
The months with the highest visibility are July, August and September (5mi).
The months with the lowest visibility are January, February, March, April, May, June, October, November and December (4mi).
Tri-City, Oregon, USA
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