December weather forecast
Renton, WA

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Weather in December

December in Renton marks the on-set of winter with lower temperatures and decreased sunlight hours. For those who enjoy colder climates, this is the ideal time, with temperatures moving between 43.3°F (6.3°C) and 34.2°F (1.2°C). The short daylight span of 8.5 hours and heightened cloudiness at 58% render a typical winter atmosphere. Despite the cold narrative of December, there is almost no snowfall, just a trace amount. As the month progresses, higher pressure readings and robust winds pervade, bringing a sense of the cold winter blues to end the year.

Temperature

In Renton, Washington, the month of December is known for its lowest average temperatures, reaching a high of 43.3°F (6.3°C) and a low of 34.2°F (1.2°C).

Humidity

The months with the highest humidity are January and December, with an average relative humidity of 85%.

Rainfall

The month with the most rainfall is December, when the rain falls for 11.2 days and typically aggregates up to 1.34" (34mm) of precipitation.

Snowfall

January through March, November and December are months with snowfall. In Renton, in December, during 1.1 snowfall days, 0.04" (1mm) of snow is typically accumulated. Throughout the year, in Renton, Washington, there are 4.9 snowfall days, and 1.18" (30mm) of snow is accumulated.

Daylight

December has the shortest days of the year, with an average of 8h and 30min of daylight.
On the first day of December, sunrise is at 7:36 am and sunset at 4:19 pm. On the last day of the month, sunrise is at 7:56 am and sunset at 4:28 pm PST.

Sunshine

The months with the least sunshine are January and December, with an average of 4.1h of sunshine.

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 low threat to health from unsafe exposure to UV radiation for average individuals.
Note: In December, the maximum UV index of 2 transforms into these recommendations:
Extended sunlight exposure does not pose significant problems for most people, except for children, infants, and people with fair skin who always need shielding. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What month is the coldest in Renton?

The month of December, characterized by an average high of 43.3°F (6.3°C) and a low of 34.2°F (1.2°C), is recognized as the coldest in Renton, Washington.

How cold is December in Renton?

The average high-temperature and low-temperature in Renton, Washington, during December are 43.3°F (6.3°C) and 34.2°F (1.2°C) respectively.

What are the most humid months in Renton?

January and December, with an average relative humidity of 85%, are most humid months in Renton.

What is the average humidity in December in Renton?

In Renton, the average relative humidity in December is 85%.

What is the wettest month in Renton?

The month with the most rainfall in Renton, Washington, is December, when the rain falls for 11.2 days and typically aggregates up to 1.34" (34mm) of precipitation.

How many days does it rain in December in Renton?

In December, in Renton, Washington, the rain falls for 11.2 days. Throughout December, 1.34" (34mm) of precipitation is accumulated.

How much does it snow in Renton in December?

In Renton, in December, snow falls for 1.1 days, with typically accumulated 0.04" (1mm) of snow.

What is the month with the shortest days in Renton?

December has the shortest days of the year in Renton, Washington, with an average of 8h and 30min of daylight.

What is the average length of the day in December in Renton?

The average day length in December in Renton is 8h and 31min.

What time are sunrise and sunset in December in Renton?

In December, on the first day of the month, sunrise is at 7:36 am and sunset at 4:19 pm. On the last day of the month, in Renton, sunrise is at 7:56 am and sunset at 4:28 pm PST.

What is the month with the least sunshine in Renton?

The months with the least sunshine are January and December, with an average of 4.1h of sunshine.

How long on average sun shines in December in Renton?

The average sunshine duration in December in Renton, Washington, is 4.1h.

What is the month with the lowest UV index in Renton?

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

What is the UV index reading in December in Renton?

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 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
Renton, WA

Average temperature in December - Renton, WA
  • Average high temperature in December: 43.3°F

The warmest months (with the highest average high temperature) are July and August (77.4°F).
The month with the lowest average high temperature is December (43.3°F).

  • Average low temperature in December: 34.2°F

The month with the highest average low temperature is August (53.6°F).
The coldest month (with the lowest average low temperature) is December (34.2°F).

Average pressure in December
Renton, WA

Average pressure in December - Renton, WA
  • Average pressure in December: 30.09"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).

Average wind speed in December
Renton, WA

Average wind speed in December - Renton, WA
  • Average wind speed in December: 4.6mph

The windiest month (with the highest average wind speed) is March (5.2mph).
The calmest month (with the lowest average wind speed) is August (3.6mph).

Average humidity in December
Renton, WA

Average humidity in December - Renton, WA
  • Average humidity in December: 85%

The months with the highest relative humidity are January and December (85%).
The months with the lowest relative humidity are July and August (68%).

Average rainfall in December
Renton, WA

Average rainfall in December - Renton, WA
  • Average rainfall in December: 1.34"

The wettest month (with the highest rainfall) is December (1.34").
The driest month (with the least rainfall) is July (0.12").

Average rainfall days in December
Renton, WA

Average rainfall days in December - Renton, WA
  • Average rainfall days in December: 11.2 days

The month with the highest number of rainy days is March (11.9 days).
The month with the least rainy days is August (3 days).

Average snowfall in December
Renton, WA

Average snowfall in December - Renton, WA
  • Average snowfall in December: 0.04"

The month with the highest snowfall is February (0.63").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in December
Renton, WA

Average snowfall days in December - Renton, WA
  • Average snowfall days in December: 1.1 days

The month with the highest number of snowfall days is February (1.7 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
Renton, WA

Average daylight in December / Average sunshine in December - Renton, WA
  • Average daylight in December: 8h and 3min

The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).

  • Average sunshine in December: 4h and 1min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are January and December (Average sunshine: 4h and 6min).

Average sunshine days in December
Renton, WA

Average sunshine days in December - Renton, WA
  • Average sunshine days in December: 17.1 days

The month with the most sunshine days is August (25.8 days).
The month with the least sunshine days is February (15.5 days).

Average UV index in December
Renton, WA

Average UV index in December - Renton, 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, November and December (UV index 2).

Average cloud cover in December
Renton, WA

Average cloud cover in December - Renton, WA
  • Average cloud cover in December: 58

The months with the most cloud cover are January and December (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in December
Renton, WA

Average visibility in December - Renton, WA
  • Average visibility in December: 5mi

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

Renton, Washington, USA

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