December weather forecast
Kennewick, WA

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Yellow night lights on the pillars of the iconic Benton Franklin Intercounty Bridge passing over the Columbia River in Kennewick, Washington
Yellow night lights on the pillars of the iconic Benton Franklin Intercounty Bridge passing over the Columbia River in Kennewick, Washington

Weather in December

December turns Kennewick into a winter wonderland with lows around 27.9°F (-2.3°C). There is an increased likelihood of snowfall, adding to the holiday season's charm. It is the perfect time for a warm cup of cocoa or a fireplace stories session, cocooned from the cold outside. The city sparkles with holiday decor, making the wintry nights magical. It's the month of short days and long, frosty nights, ending the year on a picturesque note.

Temperature

Kennewick's coldest temperatures are experienced in December, with average high temperatures of 38.3°F (3.5°C) and lows of 27.9°F (-2.3°C).

Humidity

The average relative humidity in December is 78%.

Rainfall

The wettest months are March and December, with an average 0.94" (24mm) of rainfall.

Snowfall

January through March, November and December are months with snowfall. In December, it is snowing for 3.1 days. Throughout December, 1.57" (40mm) of snow is accumulated. Throughout the year, in Kennewick, there are 9.7 snowfall days, and 5.2" (132mm) of snow is accumulated.

Daylight

December has the shortest days of the year, with an average of 8h and 42min of daylight.
On the first day of the month, sunrise is at 7:19 am and sunset at 4:12 pm. On the last day of December, sunrise is at 7:39 am and sunset at 4:20 pm PST.

Sunshine

The average sunshine in December is 5.5h.

UV index

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for the ordinary person.
Note: The daily maximum UV index of 2 in December interprets into the following advice:
Despite most people tolerating extended sun exposure, it is critical to always protect those with sensitive skin, infants, and children. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes. 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 is the coldest time of year?

The coldest time of the year in Kennewick is December, with temperatures averaging a high of 38.3°F (3.5°C) and a low of 27.9°F (-2.3°C).

How cold does it get in December?

In December, in Kennewick, the average high-temperature is 38.3°F (3.5°C), and the average low-temperature is 27.9°F (-2.3°C).

What is the average humidity in December?

In Kennewick, the average relative humidity in December is 78%.

What is the wettest month?

The months with the most rainfall are March and December, with an average 0.94" (24mm) of precipitation.

How much does it rain in Kennewick in December?

In Kennewick, in December, during 11.5 rainfall days, 0.94" (24mm) of precipitation is typically accumulated.

How much does it snow in December?

In Kennewick, during December, snow falls for 3.1 days and regularly aggregates up to 1.57" (40mm) of snow.

What is the month with the shortest days?

The month with the shortest days in Kennewick is December, with an average of 8h and 42min of daylight.

What is the average length of the day in December?

In Kennewick, the average day length in December is 8h and 41min.

When is the sunrise / sunset in December?

On the first day of December, sunrise is at 7:19 am and sunset at 4:12 pm. On the last day of the month, sunrise is at 7:39 am and sunset at 4:20 pm PST.

How many hours of sunshine does Kennewick have in December?

In December, the average sunshine duration is 5.5h.

What is the month with the lowest UV index?

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

How high is the UV index in December?

The average daily maximum UV index in December is 2. A UV Index reading 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
Kennewick, WA

Average temperature in December - Kennewick, WA
  • Average high temperature in December: 38.3°F

The warmest month (with the highest average high temperature) is July (90.1°F).
The month with the lowest average high temperature is December (38.3°F).

  • Average low temperature in December: 27.9°F

The month with the highest average low temperature is August (64°F).
The coldest month (with the lowest average low temperature) is December (27.9°F).

Average pressure in December
Kennewick, WA

Average pressure in December - Kennewick, WA
  • Average pressure in December: 30.16"Hg

The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).

Average wind speed in December
Kennewick, WA

Average wind speed in December - Kennewick, WA
  • Average wind speed in December: 5.8mph

The windiest month (with the highest average wind speed) is April (8.5mph).
The calmest month (with the lowest average wind speed) is December (5.8mph).

Average humidity in December
Kennewick, WA

Average humidity in December - Kennewick, WA
  • Average humidity in December: 78%

The month with the highest relative humidity is January (80%).
The month with the lowest relative humidity is July (35%).

Average rainfall in December
Kennewick, WA

Average rainfall in December - Kennewick, WA
  • Average rainfall in December: 0.94"

The wettest months (with the highest rainfall) are March and December (0.94").
The driest month (with the least rainfall) is July (0.2").

Average rainfall days in December
Kennewick, WA

Average rainfall days in December - Kennewick, WA
  • Average rainfall days in December: 11.5 days

The month with the highest number of rainy days is March (13.3 days).
The month with the least rainy days is July (3.5 days).

Average snowfall in December
Kennewick, WA

Average snowfall in December - Kennewick, WA
  • Average snowfall in December: 1.57"

The month with the highest snowfall is February (2.2").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in December
Kennewick, WA

Average snowfall days in December - Kennewick, WA
  • Average snowfall days in December: 3.1 days

The month with the highest number of snowfall days is December (3.1 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
Kennewick, WA

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

The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 5h and 24min).

Average sunshine days in December
Kennewick, WA

Average sunshine days in December - Kennewick, WA
  • Average sunshine days in December: 16 days

The month with the most sunshine days is July (25.7 days).
The month with the least sunshine days is March (15.4 days).

Average UV index in December
Kennewick, WA

Average UV index in December - Kennewick, 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
Kennewick, WA

Average cloud cover in December - Kennewick, WA
  • Average cloud cover in December: 43

The month with the most cloud cover is January (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 9).

Average visibility in December
Kennewick, WA

Average visibility in December - Kennewick, WA
  • Average visibility in December: 6mi

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

Kennewick, Washington, USA

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