December weather forecast
Corvallis, OR

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A large river with two bridges across it in the city of Corvalis, Oregon, home to the famed Oregon State University
A large river with two bridges across it in the city of Corvalis, Oregon, home to the famed Oregon State University

Weather in December

Winter descends in full force on Corvallis, Oregon in December. Cold temperatures combined with limited sunshine and shorter daylight hours create chilly conditions, perfect for indoor activities and cozy fireplaces. Rainfall reaches its peak for the year, contributing to the damp, colder climate. Resurfacing from November, snowfall increases slightly to 0.24" (6mm), adding a touch of winter magic to the landscape. The end of the year is shrouded in more cloud covers than previous months, concluding the weather cycle in a cozy, wintry fold.

Temperature

The coldest time of the year is December, with temperatures averaging a high of 44.8°F (7.1°C) and a low of 34.2°F (1.2°C).

Humidity

December is the most humid month, with an average relative humidity of 89%.

Rainfall

The month with the most rainfall is December, when the rain falls for 19.1 days and typically aggregates up to 4.8" (122mm) of precipitation.

Snowfall

January through March, November and December are months with snowfall. In Corvallis, in December, snow falls for 0.5 days, with typically accumulated 0.24" (6mm) of snow. Throughout the year, there are 4.6 snowfall days, and 3.27" (83mm) of snow is accumulated.

Daylight

December has the shortest days of the year in Corvallis, with an average of 8h and 54min of daylight.
On the first day of December, sunrise is at 7:30 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:49 am and sunset at 4:43 pm PST.

Sunshine

The average sunshine in December is 3.9h.

UV index

The months with the lowest UV index in Corvallis are January, February, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: The maximum UV index, 2 during December, leads to the following recommendations:
Though extended exposure to the sun typically does not concern most people, it is crucial to always shield children, infants, and those with sensitive skin. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.

Frequently asked questions

What time of the year is the coldest?

During the coldest month in Corvallis, December, temperatures average a high of 44.8°F (7.1°C) and a low of 34.2°F (1.2°C).

What are the temperatures in Corvallis in December?

The average high-temperature, in December, in Corvallis, is 44.8°F (7.1°C), while the average low-temperature is 34.2°F (1.2°C).

What is the most humid month in Corvallis?

December is the most humid month in Corvallis, with an average relative humidity of 89%.

What is the average humidity in December?

In December, the average relative humidity is 89%.

What is the rainiest month?

The month with the most rainfall is December, when the rain falls for 19.1 days and typically aggregates up to 4.8" (122mm) of precipitation.

How many days does it rain in December?

In December, the rain falls for 19.1 days. Throughout December, 4.8" (122mm) of precipitation is accumulated.

How many days does it snow in December?

In Corvallis, in December, during 0.5 snowfall days, 0.24" (6mm) of snow is typically accumulated.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 8h and 54min of daylight.

How many hours of daylight does Corvallis have in December?

In December, the average day length is 8h and 53min.

When are sunrise and sunset in December?

On the first day of December, sunrise is at 7:30 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:49 am and sunset at 4:43 pm PST.

How many hours of sunshine does Corvallis have in December?

In Corvallis, the average sunshine duration in December is 3.9h.

When is the lowest UV index?

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.

What is the UV index reading in December in Corvallis?

In December, the average daily maximum UV index is 2. A UV Index of 2, and less, symbolizes a low health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Corvallis, OR

Average temperature in December - Corvallis, OR
  • Average high temperature in December: 44.8°F

The warmest month (with the highest average high temperature) is August (80.4°F).
The month with the lowest average high temperature is December (44.8°F).

  • Average low temperature in December: 34.2°F

The month with the highest average low temperature is August (52°F).
The coldest month (with the lowest average low temperature) is December (34.2°F).

Average pressure in December
Corvallis, OR

Average pressure in December - Corvallis, 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
Corvallis, OR

Average wind speed in December - Corvallis, OR
  • Average wind speed in December: 4.6mph

The windiest month (with the highest average wind speed) is March (4.9mph).
The calmest month (with the lowest average wind speed) is September (3.9mph).

Average humidity in December
Corvallis, OR

Average humidity in December - Corvallis, OR
  • Average humidity in December: 89%

The month with the highest relative humidity is December (89%).
The month with the lowest relative humidity is August (69%).

Average rainfall in December
Corvallis, OR

Average rainfall in December - Corvallis, OR
  • Average rainfall in December: 4.8"

The wettest month (with the highest rainfall) is December (4.8").
The driest month (with the least rainfall) is July (0.28").

Average rainfall days in December
Corvallis, OR

Average rainfall days in December - Corvallis, OR
  • Average rainfall days in December: 19.1 days

The month with the highest number of rainy days is March (20.9 days).
The month with the least rainy days is August (4.5 days).

Average snowfall in December
Corvallis, OR

Average snowfall in December - Corvallis, OR
  • Average snowfall in December: 0.24"

The month with the highest snowfall is February (1.77").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in December
Corvallis, OR

Average snowfall days in December - Corvallis, OR
  • Average snowfall days in December: 0.5 days

The month with the highest number of snowfall days is February (1.8 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
Corvallis, OR

Average daylight in December / Average sunshine in December - Corvallis, 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: 3h and 5min

The months with the most sunshine are July and August (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 3h and 36min).

Average sunshine days in December
Corvallis, OR

Average sunshine days in December - Corvallis, OR
  • Average sunshine days in December: 10.2 days

The month with the most sunshine days is July (24.3 days).
The month with the least sunshine days is February (8.4 days).

Average UV index in December
Corvallis, OR

Average UV index in December - Corvallis, OR
  • Average UV index in December: 2

The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in December
Corvallis, OR

Average cloud cover in December - Corvallis, OR
  • Average cloud cover in December: 61

The month with the most cloud cover is February (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 25).

Average visibility in December
Corvallis, OR

Average visibility in December - Corvallis, OR
  • Average visibility in December: 4mi

The months with the highest visibility are June, July, August, September and October (5mi).
The months with the lowest visibility are January, February, March, April, May, November and December (4mi).

Corvallis, Oregon, USA

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