Weathermondo.com
United StatesThe weather in December in Seattle
It's cold in December in Seattle with an average temperature of 9°C. Temperatures this month range from a low of 7°C to a high of 10°C. At night, you can expect temperatures between 2°C and 6°C.
Looking for sun? December isn’t a good month to be in Seattle. There’s too much chance of rain this month.
Average temperatures and precipitation
This chart shows the average daily maximum and minimum temperatures (in degrees Celsius) and precipitation (in millimeters) in December for Seattle, Washington. A low precipitation value usually indicates little to no rainfall on that day in recent years, while a higher value suggests more frequent rainfall.
Temperature records
With 20°C in 2014, Seattle reached the highest temperature in December over the past 10 years. The lowest daytime temperature in this month was -5°C in 2021. The extreme nighttime temperatures ranged from a lowest recorded value of -8°C to a highest value of 13°C.
Water temperature
The water temperature at Seattle is 9°C this month. This is too cold to swim without protective gear.
Precipitation and snowfall
In December, there is an average of 121 mm of precipitation, spread over 15 days. Of the total precipitation, about 2,5 cm falls as snow in December. The wind speed is around 3 Bft, mostly coming from the Southeast.
Daily weather in December for Seattle
Click on any day in December to get detailed info about the usual weather on that day in Seattle. Check out the historical temperatures and precipitation over the past 10 years on this day.
December weather comparison
| Seattle | New York | |
|---|---|---|
| Average temperature | 9°C | 9°C |
| Max. temperature | 10°C | 12°C |
| Min. temperature | 2°C | -5°C |
| Total precipitation | 121 mm | 133 mm |
| Rainy days | 15 days | 17 days |
| Total snowfall | 2,5 cm | 9,7 cm |
| Snowy days | 1 day | 3 days |
Start of December
The month of December starts in Seattle with cold temps, averaging around 10°C during the day and nights around 5°C.
Mid December
By mid-December, daytime temps stay steady at around 10°C, with nights around 4°C. During this part of the month, you might see regular precipitation, but there will also be some sunny days.
End of December
By the end of December, the average daytime temperature in Seattle is around 8°C, while nighttime temps are about 3°C. A shower might pop up, but overall, the weather will be dry and sunny.
Find affordable trips to Seattle
UV index
The UV index is a maximum of 2 this month. That's a low value on the intensity scale of 1 to 11. The risk of sunburn is minimal at this time.
Check out the climate of Seattle for all months and discover the best travel time
Temperature charts
These charts show the average temperatures in December in Seattle, Washington. The temperatures are shown in degrees Celsius and are calculated based on data from the past 10 years.
Daily Temperature in December in Seattle
Temperature in December in Seattle over the years
Precipitation charts
These charts show the average amount of precipitation in December in Seattle, Washington. Precipitation is always measured as water, even when it falls as snow or hail The amount of precipitation is displayed in millimeters, while snowfall is shown in centimeters.
Daily Precipitation in December in Seattle
Total precipitation in December in Seattle over the years
Daily Snowfall in December in Seattle
Snowfall in December in Seattle per year
Daily UV index in December in Seattle
This chart shows the average daily UV index in December in Seattle, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Weather experiences in December in Seattle
Have you been to Seattle in December?
Share your weather experience in December in Seattle.
Average weather in Seattle by month
Click on a month below to see detailed weather info for Seattle. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.