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

Thinking of visiting SeaTac in September? Check the weather first! Thinking about a visit? Explore this page for a full overview of the weather conditions this month.

Temperatures

Experience perfect weather in SeaTac during September, featuring pleasant temperatures and moderate rainfall. Experience the summer season in September. Daytime temperatures generally peak at 22°C, but after sunset, they often decrease to around 12°C.

Precipitation

SeaTac in September usually receives moderate rainfall, averaging around 49 mm for the month. Climate data suggests that about 9 days will experience rainfall.

Average sunshine

Expect sunny days throughout the month, with an estimated 220 hours of sunshine. Making it a pleasant time to visit SeaTac.

If you're a fan of comfortable temperatures and drier conditions, September is a great time to visit. June, July, August and September generally stand out with 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 September

Min Temperature 12°C  

Max Temperature 22°C  

Chance of Rain 31%  

Precipitation 49 mm  

Rainy days 9 days  

Humidity 73% *  

Windspeed 14 km/h *  

Sunshine 220 hours *  

Percentage Sunshine 59% *  

Where to go in the United States of America in September

Find out more about the weather in the United States of America and which places have the best travel 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 this month?

For visitors traveling to SeaTac, we recommend wearing layers. So maybe a skirt, t-shirt, shorts for during the day and jeans and a warm jacket for some days and evenings. Bring a rain jacket in case it rains during your stay. Plan on layering your clothes.

What To Do

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

Cycling

10/10

Walking

10/10

Barbeque

9/10

Camping

10/10

Outdoor sports

10/10

Interested in more climate information?

This site 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 travel conditions. Find out where to go with our weather planner.