Normal weather for Seattle in December
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.
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.
Seattle in December |
New York | ||
|---|---|---|---|
 Average Temperature |
9°C | 9°C | |
 High Temp |
10°C | 12°C | |
| Low Temp |
7°C | 4°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. You can expect regular precipitation, but there will also be some sunny days in the early part of the month.
With the temperature difference between day and night, it’s smart to wear layers. During the day, go for a warm jacket, sweater or hoodie, and long pants. For the evening and morning, we recommend a thick jacket, sweater, and long pants.
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.
Since it cools down at night, it’s a good idea to wear layers. During the day, go for a warm jacket, sweater or hoodie, and long pants. For the evening and morning, we recommend a thick jacket, sweater, and long pants.
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.
Because temperatures drop in the evening, wearing layers is recommended. During the day, wear a thick jacket, sweater, and long pants. For the evening and morning, we recommend a heavy winter coat, sweater, long pants, beanie, and gloves.
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Water temperature
The water temperature at Seattle is 9°C this month. This is too cold to swim without protective gear.
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.
Is December a good time to visit Seattle?
Looking for sun? December isn’t a good month to be in Seattle. There’s too much chance of rain this month.
Temperature records for Seattle in December
Check out the climate of Seattle for all months and discover the best travel time
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Daily Temperature in December in Seattle
This chart shows the average daily high and low temperatures in December for Seattle, in degrees Celsius. The red line represents the highs, and the blue line shows the lows. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, provide the average temperatures for this month.
Daily Precipitation in December in Seattle
The chart below shows the average daily precipitation in December for Seattle, measured in millimeters over the past few years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are listed at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that it rained more often. But remember, it’s just an average, and every day can be different. Based on historical weather data for December, you can expect about 15 days of precipitation in Seattle.
Daily Snowfall in December in Seattle
This chart shows the average daily snowfall in December in Seattle, measured in centimeters. The bottom of the chart shows the days of the month. The data is based on historical measurements and gives an idea of the average snowfall in December.
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.
Temperature in December in Seattle Over the Years
This chart shows the average temperature in December in Seattle, measured in degrees Celsius, over the past few years.
Total Precipitation in December in Seattle Over the Years
This chart shows the average precipitation in December in Seattle, measured in millimeters over the past years. Precipitation is always measured as water, whether it’s snow or hail.
Snowfall in December in Seattle per year
This chart shows the average snowfall in December in Seattle, measured in centimeters, over the past few years.
Daily Climate 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.
Weather experiences in December in Seattle
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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.
