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
In Jefferson, the lowest temperatures are generally noted in December, averaging a high of 45.5°F (7.5°C) and a low of 34.5°F (1.4°C).Humidity
The months with the highest humidity are February and December, with an average relative humidity of 87%.Rainfall
December is the month with the most rainfall. Rain falls for 18.5 days and accumulates 3.98" (101mm) of precipitation.Snowfall
Months with snowfall are January through March, November and December. In Jefferson, in December, snow falls for 0.5 days, with typically accumulated 0.31" (8mm) of snow. In Jefferson, during the entire year, snow falls for 4.3 days and aggregates up to 2.64" (67mm) of snow.Daylight
With an average of 8h and 54min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:29 am and sunset at 4:32 pm. On the last day of December, sunrise is at 7:49 am and sunset at 4:41 pm PST.
Sunshine
In Jefferson, the average sunshine in December is 4.3h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for the ordinary person.Note: A daily high UV index of 2 in December leads to these guidelines:
Most people face no serious problems with extended sun exposure, but those with fair skin, infants, and children always need protection. Minimize direct exposure to the Sun during midday when its radiation is at its peak. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Be alert to the fact! The reflection from snow can nearly double the UV radiation of the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the coldest?
What is the average December temperature?
What are the most humid months?
What is the average humidity in December?
What is the wettest month?
How many days does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December in Jefferson?
What time are sunrise and sunset in December in Jefferson?
How long on average sun shines in December?
When is the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Jefferson, OR
- Average high temperature in December: 45.5°F
The warmest month (with the highest average high temperature) is August (81.9°F).
The month with the lowest average high temperature is December (45.5°F).
- Average low temperature in December: 34.5°F
The month with the highest average low temperature is August (52.9°F).
The coldest month (with the lowest average low temperature) is December (34.5°F).
Average pressure in December
Jefferson, OR
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).
Average wind speed in December
Jefferson, OR
- Average wind speed in December: 4.9mph
The windiest month (with the highest average wind speed) is March (5.1mph).
The calmest month (with the lowest average wind speed) is August (4mph).
Average humidity in December
Jefferson, OR
- Average humidity in December: 87%
The months with the highest relative humidity are February and December (87%).
The month with the lowest relative humidity is August (66%).
Average rainfall in December
Jefferson, OR
- Average rainfall in December: 3.98"
The wettest month (with the highest rainfall) is December (3.98").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in December
Jefferson, OR
- Average rainfall days in December: 18.5 days
The month with the highest number of rainy days is March (20 days).
The month with the least rainy days is August (3.9 days).
Average snowfall in December
Jefferson, OR
- Average snowfall in December: 0.31"
The month with the highest snowfall is February (1.3").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Jefferson, OR
- Average snowfall days in December: 0.5 days
The month with the highest number of snowfall days is February (1.9 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
Jefferson, OR
- Average daylight in December: 8h and 5min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in December: 4h and 2min
The month with the most sunshine is August (Average sunshine: 11h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 6min).
Average sunshine days in December
Jefferson, OR
- Average sunshine days in December: 10.7 days
The month with the most sunshine days is July (25.7 days).
The month with the least sunshine days is February (9 days).
Average UV index in December
Jefferson, 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
Jefferson, OR
- Average cloud cover in December: 57
The month with the most cloud cover is February (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 21).
Average visibility in December
Jefferson, OR
- Average visibility in December: 5mi
The months with the highest visibility are July, August and September (6mi).
The month with the lowest visibility is February (4mi).
Jefferson, Oregon, USA
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