Average monthly rainfall and snow in Seattle (Washington State), the United States of America (inches) (2024)

FAQs

What is the average monthly rainfall in Seattle Washington? ›

Seattle, Washington receives 965.4 mm (38 in) of rainfall per year, or 80.5 mm (3.2 in) per month. On average there are 150 days per year with more than 0.1 mm (0.004 in) of rainfall (precipitation) or 12.5 days with a quantity of rain, sleet, snow etc. per month.

Seattle averages just 6.3 inches of snow a winter, although several winters—especially during the 1950s and 60s—have seen much more. Seattle's official snowfall records were taken at Sea-Tac Airport from 1945 through the winter of 1995-96, and again from the winter of 2004-05 onward.

Annual precipitation ranges from seven to nine inches near the confluence of the Snake and Columbia Rivers, 15 to 30 inches along the eastern border and 75 to 90 inches near the summit of the Cascade Mountains. During July and August, it is not unusual for four to eight weeks to pass with only a few scattered showers.

"Annual precipitation averages 39 inches (990 millimeters), with the heaviest rains falling from October through March." Seattle's Convention and Visitor's Bureau - Seattle Fact Sheet.

The mean temperature prevailing in the city of Seattle is recorded as 10.8 °C | 51.5 °F, according to statistical data. Precipitation here is about 1386 mm | 54.6 inch per year. Seattle is located in the northern hemisphere. The balmy days of Summer commence at the end of June and conclude in September.

Rainy day in Capitol Hill, Seattle. Seattle experiences around 150 days with at least 0.01 inches (0.25 mm) precipitation each year. Records for the Seattle City area date back to 1894, with records at Seattle-Tacoma International Airport beginning in 1945, a location notably not within Seattle.

Snow in Washington

Snowpack levels across Washington are currently 27% of normal. Washington's annual average snowfall total is 277". The table below shows the snow cover in Washington.

The 12-Month Long-Range Weather Report From The 2024 Old Farmer's Almanac. Winter temperatures will be colder than normal, with below-normal precipitation and snowfall. The coldest periods will be in mid-November, late December, and mid-January. The snowiest periods will occur in mid- to late December and mid-January.

What is America's average rainfall? ›

Annual precipitation volume in the United States 1900-2023

In 2023, the United States saw some 29.5 inches of precipitation. The main forms of precipitation include hail, drizzle, rain, sleet and snow. Since the turn of the century, 2012 was the driest year on record with an annual precipitation of 27.53 inches.

Snow in Seattle

Seattle's annual average snowfall total is 331". The table below shows the snow cover in Seattle. Note that snowpack levels across Seattle aren't reported during the off-season period.

Between 1991 and 2020, normal precipitation for the month of June in the Seattle area is 1.57 inches, according to historic data from the National Weather Service. That's the third lowest total monthly precipitation. Ditto for Sea-Tac Airport, where the normal is 1.45 inches.

Seattle was submerged in record rainfall nine years ago, with 5.02 inches falling at Sea-Tac Airport on Oct. 20, 2003--making for the wettest day in Seattle history.

Seattle is in the rain shadow of the Olympic Mountains and gets about 30 inches of rain a year. Mind you it can rain viciously in Seattle (ask me how I know) but lots of cities get as much or more. Seattle is in the 30–40 inch band. Look at the northeast corner of the Olympic Peninsula.

Hilo, Hawaii

It's also known as the wettest place in the United States, averaging about 12 in. of rain per month. Its wettest month is December where it sees an average of 19 inches of rainfall for the month. But this shouldn't surprise you.

At 37.7 inches of precipitation annually, Seattle ranks 32nd among the nation's 50 largest cities. Notice that most of the cities with more rainfall are located east of the Mississippi River, as shown in the map below made by climatologist Brian Brettschneider.

“It rains nine months a year in Seattle,” a famous line in the movie Sleepless in Seattle. For those of us who live in the Pacific Northwest, we know this quote to be true. But we are surrounded by green, so green and lush because of the rain. Surrounded by green!