December weather forecast
Forest Grove, OR

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Weather in December

December rounds off the year in Forest Grove, with the city caught in the full swing of winter. Temperatures between 43°F (6.1°C) and 33.1°F (0.6°C) can be expected this month. The chances of snowfall increase marginally, making December one of the colder months. Despite the piercing cold, the festive charm of the city keeps spirits high. As December signs off to ring in the new year, the chilly weather promises to usher in a cold January.

Temperature

December, with its high-temperature average of 43°F (6.1°C) and a low-temperature average of 33.1°F (0.6°C), is the coldest month in Forest Grove.

Humidity

February and December, with an average relative humidity of 88%, are the most humid months in Forest Grove.

Rainfall

In Forest Grove, in December, during 19.4 rainfall days, 5.39" (137mm) of precipitation is typically accumulated. In Forest Grove, during the entire year, the rain falls for 183.5 days and collects up to 34.45" (875mm) of precipitation.

Snowfall

Months with snowfall are January through March, November and December. In December, in Forest Grove, it is snowing for 0.7 days. Throughout December, 0.43" (11mm) of snow is accumulated. Throughout the year, in Forest Grove, there are 7.1 snowfall days, and 4.69" (119mm) of snow is accumulated.

Daylight

With an average of 8h and 48min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 7:33 am and sunset at 4:30 pm. On the last day of December, in Forest Grove, sunrise is at 7:52 am and sunset at 4:39 pm PST.

Sunshine

The average sunshine in December is 3.6h.

UV index

In December, the average daily maximum UV index is 2. A UV Index of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV rays for the average person.
Note: A daily high UV index of 2 in December leads to these guidelines:
Prolonged sun exposure should always be prevented in babies, children, and those with sensitive skin. The solar radiation around mid-day is intense; avoid the Sun and stay safe. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key. Take precaution! The reflection from snow can almost double the UV radiation of the Sun.
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Frequently asked questions

What month is the coldest in Forest Grove?

In Forest Grove, Oregon, the average lowest temperatures are observed in December, with a high of 43°F (6.1°C) and a low of 33.1°F (0.6°C).

Is it cold in Forest Grove during December?

The high-temperature in Forest Grove, Oregon, during December is 43°F (6.1°C) and the low-temperature is 33.1°F (0.6°C).

What are the most humid months in Forest Grove?

February and December, with an average relative humidity of 88%, are most humid months.

What is the average humidity in December in Forest Grove?

In December, the average relative humidity in Forest Grove, Oregon, is 88%.

How many days does it rain in December in Forest Grove?

In December, the rain falls for 19.4 days. Throughout December, 5.39" (137mm) of precipitation is accumulated.

How much does it snow in Forest Grove in December?

In December, in Forest Grove, it is snowing for 0.7 days. Throughout December, 0.43" (11mm) of snow is accumulated.

What is the month with the shortest days in Forest Grove?

The month with the shortest days is December, with an average of 8h and 48min of daylight.

What is the average length of the day in December in Forest Grove?

In Forest Grove, Oregon, the average day length in December is 8h and 46min.

What time are sunrise and sunset in December in Forest Grove?

In December, on the first day of the month, sunrise is at 7:33 am and sunset at 4:30 pm. On the last day of the month, in Forest Grove, Oregon, sunrise is at 7:52 am and sunset at 4:39 pm PST.

How long on average sun shines in December in Forest Grove?

In December, the average sunshine duration in Forest Grove is 3.6h.

What is the UV index intensity in December in Forest Grove?

In December, the average daily maximum UV index in Forest Grove, Oregon, is 2. A UV Index estimate of 2, and below, represents a minimal hazard to health 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
Forest Grove, OR

Average temperature in December - Forest Grove, OR
  • Average high temperature in December: 43°F

The warmest month (with the highest average high temperature) is August (79.3°F).
The month with the lowest average high temperature is December (43°F).

  • Average low temperature in December: 33.1°F

The month with the highest average low temperature is August (53.2°F).
The coldest month (with the lowest average low temperature) is December (33.1°F).

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Average pressure in December
Forest Grove, OR

Average pressure in December - Forest Grove, OR
  • Average pressure in December: 30.09"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).

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Average wind speed in December
Forest Grove, OR

Average wind speed in December - Forest Grove, OR
  • Average wind speed in December: 4.5mph

The windiest month (with the highest average wind speed) is March (4.9mph).
The calmest month (with the lowest average wind speed) is August (4mph).

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Average humidity in December
Forest Grove, OR

Average humidity in December - Forest Grove, OR
  • Average humidity in December: 88%

The months with the highest relative humidity are February and December (88%).
The month with the lowest relative humidity is August (69%).

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Average rainfall in December
Forest Grove, OR

Average rainfall in December - Forest Grove, OR
  • Average rainfall in December: 5.39"

The wettest month (with the highest rainfall) is January (5.47").
The driest months (with the least rainfall) are July and August (0.47").

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Average rainfall days in December
Forest Grove, OR

Average rainfall days in December - Forest Grove, OR
  • Average rainfall days in December: 19.4 days

The month with the highest number of rainy days is March (21.4 days).
The month with the least rainy days is August (6.2 days).

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Average snowfall in December
Forest Grove, OR

Average snowfall in December - Forest Grove, OR
  • Average snowfall in December: 0.43"

The month with the highest snowfall is February (1.54").
The months with the least snowfall are April, May, June, July, August, September and October (0").

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Average snowfall days in December
Forest Grove, OR

Average snowfall days in December - Forest Grove, OR
  • Average snowfall days in December: 0.7 days

The month with the highest number of snowfall days is February (2.9 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

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Average daylight in December /
Average sunshine in December
Forest Grove, OR

Average daylight in December / Average sunshine in December - Forest Grove, OR
  • Average daylight in December: 8h and 5min

The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).

  • Average sunshine in December: 3h and 4min

The month with the most sunshine is August (Average sunshine: 10h and 24min).
The months with the least sunshine are January and February (Average sunshine: 3h and 30min).

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Average sunshine days in December
Forest Grove, OR

Average sunshine days in December - Forest Grove, OR
  • Average sunshine days in December: 10.1 days

The month with the most sunshine days is August (22 days).
The month with the least sunshine days is March (7.6 days).

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Average UV index in December
Forest Grove, OR

Average UV index in December - Forest Grove, OR
  • Average UV index in December: 2

The months with the highest UV index are June and July (UV index 5).
The month with the lowest UV index is November (UV index 1).

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Average cloud cover in December
Forest Grove, OR

Average cloud cover in December - Forest Grove, OR
  • Average cloud cover in December: 64

The month with the most cloud cover is February (Cloud cover 66).
The month with the least cloud cover is August (Cloud cover 28).

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Average visibility in December
Forest Grove, OR

Average visibility in December - Forest Grove, OR
  • Average visibility in December: 4mi

The months with the highest visibility are July and August (6mi).
The months with the lowest visibility are January, February, March, November and December (4mi).

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Forest Grove, Oregon, USA

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