Olympia
Washington, USA
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
Olympia, WA

The calm Capitol Lake overlooking the Washington State Capitol building in Olympia, Washington
The calm Capitol Lake overlooking the Washington State Capitol building in Olympia, Washington
December, the first month of the winter, in Olympia, is still a chilly month, with average temperature varying between 44.2°F (6.8°C) and 32.5°F (0.3°C).

Temperature

The coldest month is December, with an average high-temperature of 44.2°F (6.8°C) and an average low-temperature of 32.5°F (0.3°C).

Humidity

December is the most humid month, with an average relative humidity of 89.1%.

Rainfall

In Olympia, during December, the rain falls for 19.6 days and regularly aggregates up to 7.5" (189.5mm) of precipitation. Throughout the year, in Olympia, there are 162.8 rainfall days, and 50" (1270mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through March, November and December. In December, in Olympia, it is snowing for 2 days. Throughout December, 2.6" (66mm) of snow is accumulated. Throughout the year, there are 6.3 snowfall days, and 10.8" (274.4mm) of snow is accumulated.

Daylight

With an average of 8.6h of daylight, December has the shortest days of the year.

Sunshine

January and December, with an average of 2h of sunshine, are months with the least sunshine in Olympia.

UV index

Months with the lowest UV index are January, November and December, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a low health risk from unprotected exposure to the Sun's UV rays for ordinary individuals.
Note: The average daily UV index of 1 transform into the following instructions:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

What is the coldest month in Olympia?

With an average high-temperature of 44.2°F (6.8°C) and an average low-temperature of 32.5°F (0.3°C), December is the coldest month.

What is the temperature in December in Olympia?

The average high-temperature, in December, in Olympia, is 44.2°F (6.8°C), while the average low-temperature is 32.5°F (0.3°C).

What is the most humid month in Olympia?

The most humid month in Olympia is December, with an average relative humidity of 89.1%.

What is the average humidity in December in Olympia?

The average relative humidity in December is 89.1%.

How many days does it rain in December in Olympia?

In December, in Olympia, the rain falls for 19.6 days. Throughout December, 7.5" (189.5mm) of precipitation is accumulated.

How much does it snow in Olympia in December?

In Olympia, in December, during 2 snowfall days, 2.6" (66mm) of snow is typically accumulated.

What is the month with the shortest days in Olympia?

December has the shortest days of the year in Olympia, with an average of 8.6h of daylight.

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

The average length of the day in December is 8.6h.

What is the month with the least sunshine in Olympia?

January and December, with an average of 2h of sunshine, are months with the least sunshine in Olympia.

How long on average sun shines in December in Olympia?

In Olympia, Washington, the average sunshine in December is 2h.

When is the lowest UV index in Olympia?

Months with the lowest UV index in Olympia, Washington, are January, November and December, with an average maximum UV index of 1.

What is the UV index intensity in December in Olympia?

In December, the average daily maximum UV index in Olympia, Washington, is 1. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from the exposure to the Sun's UV rays.
Average temperature in December - Olympia, WA
  • Average high temperature in December: 6.8°C

The warmest month (with the highest average high temperature) is August (25.4°C).
The month with the lowest average high temperature is December (6.8°C).

  • Average low temperature in December: 0.3°C

The month with the highest average low temperature is July (10.4°C).
The coldest month (with the lowest average low temperature) is December (0.3°C).

Average humidity in December - Olympia, WA
  • Average humidity in December: 89.1%

The month with the highest relative humidity is December (89.1%).
The month with the lowest relative humidity is July (70.8%).

Average rainfall in December - Olympia, WA
  • Average rainfall in December: 189.5mm

The wettest month (with the highest rainfall) is November (219.2mm).
The driest month (with the lowest rainfall) is July (16mm).

Average rainfall days in December - Olympia, WA
  • Average rainfall days in December: 19.6 days

The month with the highest number of rainy days is November (20.1 days).
The month with the lowest number of rainy days is July (4.6 days).

Average snowfall in December - Olympia, WA
  • Average snowfall in December: 66mm

The month with the highest snowfall is February (119.4mm).
Months with the lowest snowfall are April, May, June, July, August, September and October (0mm).

Average snowfall days in December - Olympia, WA
  • Average snowfall days in December: 2 days

The month with the highest number of snowfall days is February (2.2 days).
Months with the lowest number of snowfall days are May, June, July, August, September and October (0 days).

Average daylight in December / Average sunshine in December - Olympia, WA
  • Average daylight in December: 8.6h

The month with the longest days is June (Average daylight: 15.8h).
The month with shortest days is December (Average daylight: 8.6h).

  • Average sunshine in December: 2h

The month with most sunshine is July (Average sunshine: 10h).
Months with least sunshine are January and December (Average sunshine: 2).

Average UV index in December - Olympia, WA
  • Average UV index in December: 1

Months with the highest UV index are June, July and August (UV index 7).
Months with the lowest UV index are January, November and December (UV index 1).