December weather forecast
Underwood, WA

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Weather in December

The first month of the winter, December, is also an icy month in Underwood, Washington, with temperature in the range of an average high of 36°F (2.2°C) and an average low of 27°F (-2.8°C).

Temperature

The coldest time of the year is December, with temperatures averaging a high of 36°F (2.2°C) and a low of 27°F (-2.8°C).

Humidity

The months with the highest humidity in Underwood are February and December, with an average relative humidity of 88%.

Rainfall

In December, the rain falls for 17.9 days. Throughout December, 5.08" (129mm) of precipitation is accumulated. In Underwood, during the entire year, the rain falls for 159.7 days and collects up to 31.42" (798mm) of precipitation.

Snowfall

January through March, November and December are months with snowfall. In Underwood, in December, snow falls for 4.1 days, with typically accumulated 3.66" (93mm) of snow. In Underwood, during the entire year, snow falls for 15.1 days and aggregates up to 14.33" (364mm) of snow.

Daylight

December has the shortest days of the year, with an average of 8h and 42min of daylight.
On the first day of December, sunrise is at 7:27 am and sunset at 4:23 pm. On the last day of the month, sunrise is at 7:46 am and sunset at 4:32 pm PST.

Sunshine

The average sunshine in December is 3.9h.

UV index

In December, the average daily maximum UV index is 2. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV rays for the average person.
Note: A maximum daily UV index of 2 during December morphs into the following directions:
It is important to always shield children, babies, and individuals with sensitive skin from prolonged exposure to the sun. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. A hat with a broad brim is indispensable, filtering out up to half of UV rays. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Updated: Jun 21, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the coldest months?

December is the coldest month, with the temperature often reaching an average high of 36°F (2.2°C) and an average low of 27°F (-2.8°C).

How cold is it in December?

The high-temperature, in December, in Underwood, is 36°F (2.2°C), while the low-temperature averages to 27°F (-2.8°C).

What is the most humid month?

The months with the highest humidity are February and December, with an average relative humidity of 88%.

What is the average humidity in December?

In Underwood, the average relative humidity in December is 88%.

How many days does it rain in December?

In Underwood, in December, it is raining for 17.9 days, with typically 5.08" (129mm) of accumulated precipitation.

How much does it snow in December?

In Underwood, Washington, during December, snow falls for 4.1 days and regularly aggregates up to 3.66" (93mm) of snow.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 8h and 42min of daylight.

What is the average length of the day in December?

In Underwood, the average day length in December is 8h and 45min.

When are sunrise and sunset in December?

On the first day of December, sunrise is at 7:27 am and sunset at 4:23 pm. On the last day of the month, sunrise is at 7:46 am and sunset at 4:32 pm PST.

How long on average sun shines in December?

The average sunshine duration in December is 3.9h.

What is the UV index reading in December?

The average daily maximum UV index in December 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
Underwood, WA

Average temperature in December - Underwood, WA
  • Average high temperature in December: 36°F

The warmest month (with the highest average high temperature) is August (78.4°F).
The month with the lowest average high temperature is December (36°F).

  • Average low temperature in December: 27°F

The month with the highest average low temperature is August (51.4°F).
The coldest month (with the lowest average low temperature) is December (27°F).

Average pressure in December
Underwood, WA

Average pressure in December - Underwood, WA
  • Average pressure in December: 30.13"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is August (29.97"Hg).

Average wind speed in December
Underwood, WA

Average wind speed in December - Underwood, WA
  • Average wind speed in December: 5.2mph

The windiest month (with the highest average wind speed) is June (6.1mph).
The calmest month (with the lowest average wind speed) is October (4.8mph).

Average humidity in December
Underwood, WA

Average humidity in December - Underwood, WA
  • 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 July (59%).

Average rainfall in December
Underwood, WA

Average rainfall in December - Underwood, WA
  • Average rainfall in December: 5.08"

The wettest month (with the highest rainfall) is January (5.67").
The driest month (with the least rainfall) is July (0.28").

Average rainfall days in December
Underwood, WA

Average rainfall days in December - Underwood, WA
  • Average rainfall days in December: 17.9 days

The month with the highest number of rainy days is March (20 days).
The month with the least rainy days is August (4.2 days).

Average snowfall in December
Underwood, WA

Average snowfall in December - Underwood, WA
  • Average snowfall in December: 3.66"

The month with the highest snowfall is February (4.76").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in December
Underwood, WA

Average snowfall days in December - Underwood, WA
  • Average snowfall days in December: 4.1 days

The month with the highest number of snowfall days is December (4.1 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
Underwood, WA

Average daylight in December / Average sunshine in December - Underwood, WA
  • Average daylight in December: 8h and 4min

The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).

  • Average sunshine in December: 3h and 5min

The month with the most sunshine is July (Average sunshine: 11h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

Average sunshine days in December
Underwood, WA

Average sunshine days in December - Underwood, WA
  • Average sunshine days in December: 9.8 days

The month with the most sunshine days is July (25.4 days).
The month with the least sunshine days is March (8.4 days).

Average UV index in December
Underwood, WA

Average UV index in December - Underwood, WA
  • 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 and November (UV index 1).

Average cloud cover in December
Underwood, WA

Average cloud cover in December - Underwood, WA
  • Average cloud cover in December: 62

The months with the most cloud cover are January and February (Cloud cover 64).
The months with the least cloud cover are July and August (Cloud cover 17).

Average visibility in December
Underwood, WA

Average visibility in December - Underwood, WA
  • Average visibility in December: 4mi

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

Underwood, Washington, USA

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