Washington Weather in September

September in Washington sees daytime temperatures around 27°C (81°F) and lows of 14°C (57°F) at night. With around 112 mm (4.4 in) of rainfall expected, it's worth packing a rain jacket.

Rainfall in Washington in September

Past climate data indicates that roughly 10 days will see rain, totalling around 112 mm (4.4 in) for the month. When it rains this month, it tends to come down fairly heavily. Showers can be substantial even if they don't last all day.

Temperature in Washington in September

In September, Washington gets high temperatures, with highs of 27°C (81°F). Nights cool to around 14°C (57°F). Conditions stay fairly consistent through the month, making it easier to plan what to wear. With lows of 14°C (57°F), nights are cool. If you're out after dark, an extra layer will keep you comfortable. The cooler air at night is also great for getting a good rest.

Sunshine in Washington in September

With approximately 235 hours of sunshine, the days are filled with clear skies. It makes it a perfect month for being outside.

If your ideal day consists of dry skies and pleasant temperatures, October typically offers the best circumstances for Washington.

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Washington's climate page.

Washington Temperature in September

Min Temperature 14°C (57°F)  

Max Temperature 27°C (81°F)  

Chance of Rain 33%  

Precipitation 112 mm (4.4 in)  

Rainy days 10 days  

Humidity 71% *  

Sunshine 235 hours *  

Percentage Sunshine 63% *  

* Data from: St. Louis, the United States of America (71 KM, 44 Miles).

What to Wear in Washington in September

Warm but pleasant conditions in Washington in September. Focus on lightweight, maybe with natural fabrics, cotton blend shirts, comfortable shorts, and breathable footwear. A light cover-up for sun protection is smart too. Expect heavy rainfall, so bring good rain protection and waterproof bags. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.

What To Do in Washington in September

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

Swimming

9/10

Cycling

7/10

Walking

7/10

Camping

6/10

Outdoor sports

7/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Washington's climate page.

More climate data for Washington

Temperature Rainfall Sunshine Humidity

See the full Washington climate overview or explore weather in the United States of America.