SeaTac weather in December (Washington State, United States of America)

How is the weather in SeaTac in December? This guide provides all the details you need.

In December, SeaTac generally has low temperatures and high rainfall. December is a winter month. Throughout the day, temperatures typically settle at around 8°C. But by evening, they drop to around 2°C. It's often the coldest month of the year, a perfect time to cozy up indoors. Make sure to bring along suitable winter clothing.

SeaTac in December usually receives high rainfall, averaging around 142 mm for the month. Typically around 20 days of rainfall is expected.

The area sees fewer sunny days, with a projection of about 54 hours of sunshine. This reduced sunlight makes it ideal for those who prefer cooler, overcast conditions over bright sunny days.

If you're looking for dry conditions and comfortable temperatures, December may not be the ideal month to visit SeaTac. June, July, August and September typically offer the best circumstances. While January, February, March, November and December tend to showcase less optimal conditions.

For an in-depth look at the yearly conditions, visit our specialized SeaTac climate page with graphs.

 

SeaTac, monthly averages in December

Min Temperature 2°C  

Max Temperature 8°C  

Chance of Rain 66%  

Precipitation 142 mm  

Rainy days 20 days  

Humidity 80% *  

Windspeed 14 km/h *  

Sunshine 54 hours *  

Percentage Sunshine 20% *  

Where to go in the United States of America in December

Find out more about the weather in the United States of America in December and which places have the best weather conditions in this month.

Weather conditions Weather

Temperatures

Precipitation

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Legend perfect weather pleasant tolerable unpleasant poor

Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C and 29°C and not too much precipitation (less than 90 mm a month).

So, what should you wear in SeaTac in December?

Wear a base layer in cold weather; this is the #1 thing you can do to increase your overall body temperature.

What To Do

We rated the following activities from 1 (least suitable) to 10 (best) to do in December.

Swimming

4/10

Cycling

4/10

Walking

4/10

Camping

3/10

Outdoor sports

4/10

Interested in more climate information?

Weather and Climate provides you with all the information you need about the climate in SeaTac.

Our site offers climate and forecast data for every country in the world. Are you going to the United States of America? On this website you can find historical weather averages for many cities in the United States of America. Not sure yet where to go? We now have a tool which recommends destinations that suit your ideal climate conditions. Find out where to go with our weather planner.