December weather forecast
Sunnyside, OR

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Weather in December

The first month of the winter, December, is also a frosty month in Sunnyside, Oregon, with an average temperature ranging between max 44.4°F (6.9°C) and min 34.3°F (1.3°C).

Temperature

December is the coldest month of the year, registering average temperatures as high as 44.4°F (6.9°C) and as low as 34.3°F (1.3°C).

Humidity

In Sunnyside, the average relative humidity in December is 83%.

Rainfall

December is the month with the most rainfall. Rain falls for 19.2 days and accumulates 5.16" (131mm) of precipitation.

Snowfall

January through March, November and December are months with snowfall. In Sunnyside, during December, snow falls for 0.9 days and regularly aggregates up to 0.51" (13mm) of snow. In Sunnyside, during the entire year, snow falls for 6.1 days and aggregates up to 4.17" (106mm) of snow.

Daylight

December has the shortest days of the year in Sunnyside, with an average of 8h and 48min of daylight.
On the first day of December, sunrise is at 7:30 am and sunset at 4:28 pm. On the last day of the month, sunrise is at 7:49 am and sunset at 4:37 pm PST.

Sunshine

The average sunshine in December is 4.4h.

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 value of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for the ordinary person.
Note: A maximum high daily UV index of 2 during December translates into the following directions:
While sun exposure does not greatly affect most, individuals with fair skin, babies, and children always need vigilant safeguarding. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.
Updated: Jul 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What month is the coldest?

December, characterized by an average high temperature of 44.4°F (6.9°C) and a low temperature of 34.3°F (1.3°C), is generally the coldest month.

Is it cold during December?

In Sunnyside, 44.4°F (6.9°C) is the average high-temperature and 34.3°F (1.3°C) is the average low-temperature during December. The average heat index (a.k.a. 'feels like', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, in August is calculated to be 84.2°F (29°C).

What is the average humidity in December?

The average relative humidity in December is 83%.

What is the rainiest month?

December is the month with the most rainfall. Rain falls for 19.2 days and accumulates 5.16" (131mm) of precipitation.

How much does it rain in December?

In Sunnyside, during December, the rain falls for 19.2 days and regularly aggregates up to 5.16" (131mm) of precipitation.

How many days does it snow in December?

In December, it is snowing for 0.9 days. Throughout December, 0.51" (13mm) of snow is accumulated.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 8h and 48min of daylight.

How many hours of daylight does Sunnyside have in December?

In Sunnyside, the average day length in December is 8h and 47min.

What time are sunrise and sunset in December?

On the first day of December, sunrise is at 7:30 am and sunset at 4:28 pm. On the last day of the month, sunrise is at 7:49 am and sunset at 4:37 pm PST.

How many hours of sunshine does Sunnyside have in December?

In Sunnyside, the average sunshine duration in December is 4.4h.

What are the months with 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 intensity in December?

The average daily maximum UV index in December is 2. A UV Index estimate of 2, and below, represents a minimal hazard to health from exposure to the Sun's UV radiation.
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
Sunnyside, OR

Average temperature in December - Sunnyside, OR
  • Average high temperature in December: 44.4°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 (44.4°F).

  • Average low temperature in December: 34.3°F

The month with the highest average low temperature is August (54°F).
The coldest month (with the lowest average low temperature) is December (34.3°F).

Average pressure in December
Sunnyside, OR

Average pressure in December - Sunnyside, 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
Sunnyside, OR

Average wind speed in December - Sunnyside, OR
  • Average wind speed in December: 5.7mph

The windiest month (with the highest average wind speed) is January (6mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).

Average humidity in December
Sunnyside, OR

Average humidity in December - Sunnyside, OR
  • Average humidity in December: 83%

The month with the highest relative humidity is February (84%).
The month with the lowest relative humidity is August (64%).

Average rainfall in December
Sunnyside, OR

Average rainfall in December - Sunnyside, OR
  • Average rainfall in December: 5.16"

The wettest month (with the highest rainfall) is December (5.16").
The driest month (with the least rainfall) is July (0.24").

Average rainfall days in December
Sunnyside, OR

Average rainfall days in December - Sunnyside, OR
  • Average rainfall days in December: 19.2 days

The month with the highest number of rainy days is March (20.3 days).
The month with the least rainy days is August (4 days).

Average snowfall in December
Sunnyside, OR

Average snowfall in December - Sunnyside, OR
  • Average snowfall in December: 0.51"

The month with the highest snowfall is February (1.5").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in December
Sunnyside, OR

Average snowfall days in December - Sunnyside, OR
  • Average snowfall days in December: 0.9 days

The month with the highest number of snowfall days is February (2.3 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
Sunnyside, OR

Average daylight in December / Average sunshine in December - Sunnyside, 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: 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 18min).

Average sunshine days in December
Sunnyside, OR

Average sunshine days in December - Sunnyside, OR
  • Average sunshine days in December: 10.5 days

The month with the most sunshine days is July (26.2 days).
The month with the least sunshine days is February (8.1 days).

Average UV index in December
Sunnyside, OR

Average UV index in December - Sunnyside, 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
Sunnyside, OR

Average cloud cover in December - Sunnyside, OR
  • Average cloud cover in December: 54

The month with the most cloud cover is February (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 22).

Average visibility in December
Sunnyside, OR

Average visibility in December - Sunnyside, OR
  • Average visibility in December: 5mi

The months with the highest visibility are July, August, September and October (6mi).
The months with the lowest visibility are January, February, March, April, May, June, November and December (5mi).

Sunnyside, Oregon, USA

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