December weather forecast
Union Gap, WA

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Weather in December

The first month of the winter, December, is also a wintry month in Union Gap, Washington, with an average temperature fluctuating between 36.9°F (2.7°C) and 25.5°F (-3.6°C).

Temperature

In Union Gap, Washington, the lowest average temperatures are observed in December, with a high of 36.9°F (2.7°C) and a low of 25.5°F (-3.6°C).

Humidity

In December, the average relative humidity is 80%.

Rainfall

In Union Gap, during December, the rain falls for 9.1 days and regularly aggregates up to 0.83" (21mm) of precipitation. In Union Gap, during the entire year, the rain falls for 82.2 days and collects up to 5.43" (138mm) of precipitation.

Snowfall

Months with snowfall are January through March, September, November and December. The month with the most snowfall is December, when snow falls for 5.4 days and typically aggregates up to 2.76" (70mm) of snow.

Daylight

December has the shortest days of the year, with an average of 8h and 36min of daylight.
On the first day of December, sunrise is at 7:26 am and sunset at 4:16 pm. On the last day of the month, sunrise is at 7:45 am and sunset at 4:24 pm PST.

Sunshine

In December, the average sunshine is 5.9h.

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 hazard from exposure to the Sun's UV radiation for ordinary individuals.
Note: In December, an average UV index of 2 transforms into the following instructions:
Despite most people tolerating extended sun exposure, it is critical to always protect those with sensitive skin, infants, and children. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Enhance your sun protection with tightly woven, yet airy clothing. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Updated: Jul 18, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What month is the coldest?

Union Gap experiences its average lowest temperatures in December, reaching a peak of 36.9°F (2.7°C) and a minimum of 25.5°F (-3.6°C).

How cold is December?

An average high-temperature, in December, in Union Gap, is 36.9°F (2.7°C) and the average low-temperature is 25.5°F (-3.6°C).

What is the average humidity in December?

In Union Gap, the average relative humidity in December is 80%.

How many days does it rain in December?

In December, the rain falls for 9.1 days. Throughout December, 0.83" (21mm) of precipitation is accumulated.

What is the snowiest month?

The month with the most snowfall is December, when snow falls for 5.4 days and typically aggregates up to 2.76" (70mm) of snow.

How much does it snow in Union Gap in December?

In Union Gap, in December, during 5.4 snowfall days, 2.76" (70mm) of snow is typically accumulated.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 8h and 36min of daylight.

How many hours of daylight does Union Gap have in December?

In December, the average day length is 8h and 38min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:26 am and sunset at 4:16 pm. On the last day of the month, sunrise is at 7:45 am and sunset at 4:24 pm PST.

How long on average sun shines in December?

The average sunshine duration in December is 5.9h.

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 in Union Gap?

In December, the average daily maximum UV index is 2. A UV Index of 2, and less, symbolizes a minimal hazard to health from 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
Union Gap, WA

Average temperature in December - Union Gap, WA
  • Average high temperature in December: 36.9°F

The warmest month (with the highest average high temperature) is August (86.5°F).
The month with the lowest average high temperature is December (36.9°F).

  • Average low temperature in December: 25.5°F

The month with the highest average low temperature is August (60.3°F).
The coldest month (with the lowest average low temperature) is December (25.5°F).

Average pressure in December
Union Gap, WA

Average pressure in December - Union Gap, WA
  • Average pressure in December: 30.14"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is August (29.93"Hg).

Average wind speed in December
Union Gap, WA

Average wind speed in December - Union Gap, WA
  • Average wind speed in December: 4.4mph

The windiest month (with the highest average wind speed) is June (7.1mph).
The calmest month (with the lowest average wind speed) is December (4.4mph).

Average humidity in December
Union Gap, WA

Average humidity in December - Union Gap, WA
  • Average humidity in December: 80%

The month with the highest relative humidity is January (81%).
The months with the lowest relative humidity are July and August (39%).

Average rainfall in December
Union Gap, WA

Average rainfall in December - Union Gap, WA
  • Average rainfall in December: 0.83"

The wettest month (with the highest rainfall) is January (0.87").
The driest month (with the least rainfall) is July (0.08").

Average rainfall days in December
Union Gap, WA

Average rainfall days in December - Union Gap, WA
  • Average rainfall days in December: 9.1 days

The month with the highest number of rainy days is March (10.8 days).
The month with the least rainy days is August (2 days).

Average snowfall in December
Union Gap, WA

Average snowfall in December - Union Gap, WA
  • Average snowfall in December: 2.76"

The month with the highest snowfall is December (2.76").
The months with the least snowfall are April, May, June, July, August and October (0").

Average snowfall days in December
Union Gap, WA

Average snowfall days in December - Union Gap, WA
  • Average snowfall days in December: 5.4 days

The month with the highest number of snowfall days is December (5.4 days).
The months with the least snowfall days are May, June, July, August and October (0 days).

Average daylight in December /
Average sunshine in December
Union Gap, WA

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

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

  • Average sunshine in December: 5h and 5min

The months with the most sunshine are July and August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 5h and 36min).

Average sunshine days in December
Union Gap, WA

Average sunshine days in December - Union Gap, WA
  • Average sunshine days in December: 17.3 days

The month with the most sunshine days is July (27.5 days).
The month with the least sunshine days is February (15.8 days).

Average UV index in December
Union Gap, WA

Average UV index in December - Union Gap, WA
  • Average UV index in December: 2

The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in December
Union Gap, WA

Average cloud cover in December - Union Gap, WA
  • Average cloud cover in December: 37

The month with the most cloud cover is January (Cloud cover 40).
The months with the least cloud cover are July and August (Cloud cover 9).

Average visibility in December
Union Gap, WA

Average visibility in December - Union Gap, WA
  • Average visibility in December: 6mi

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

Union Gap, Washington, USA

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