How Many Sunny Days Does Seattle Get Per Year?
Seattle, Washington is known for its high annual rainfall and bleak daylight hours in the winter months. But how many sunny days in Seattle can you expect in an average year? Is it really as bad as the entire Pacific Northwest is being painted?
Let’s explore Seattle’s weather to figure out how many sunny days per year it gets, how sunny it is compared to other cities, and how many days of rain it gets.
All climate data in this article comes from the NOAA (National Oceanic and Atmospheric Administration).
Here’s the Number of Sunny Days in Seattle, Washington
According to the NOAA, Seattle-Tacoma Airport, the biggest airport located close to the city, has 2,170 sunshine hours.
With the number of sunshine hours and percent possible sunshine we can calculate the average number of days that get at least some sun. Admittedly, it’s a rough estimate based on an imperfect methodology but we’ll land somewhere in the ballpark. Note that the numbers may be slightly different for downtown Seattle since I use climate data from the airport.
Here are my calculations for the number of sunny days in the Seattle area:
Month | Sunshine hours | Percent possible sunshine | Average sunny days |
---|---|---|---|
January | 69.8 | 25% | 7.75 |
February | 108.8 | 38% | 10.64 |
March | 178.4 | 48% | 14.88 |
April | 207.3 | 51% | 15.3 |
May | 253.7 | 54% | 16.74 |
June | 268.4 | 56% | 16.8 |
July | 312 | 65% | 20.15 |
August | 281.4 | 64% | 19.84 |
September | 221.7 | 59% | 17.7 |
October | 142.6 | 42% | 13.02 |
November | 72.7 | 26% | 7.8 |
December | 52.9 | 20% | 6.2 |
According to this data, Seattle has about 167 sunny days. This means that it has 198 cloudy days. The sunniest month is July with 20 days of sun. The least sunny month is December with only 6 days of sunshine, so not only sun rises late but it’s also unlikely you’ll see any sun.
While Seattle may not be a particularly sunny city for US standards, worldwide it isn’t that cloudy. Many cities in Europe, located in the temperate zone of the continent in countries like the United Kingdom, Germany, and the Netherlands have much fewer sunny days per year.
Please remember that the available data suggests how many days get some sun. It doesn’t mean that these are Arizona-style blue sky days. It means there’s some sun and this may mean a partly cloudy or a clear day.
Sunshine Hours in Seattle Compared to Other Cities
By itself, the number of sunshine hours in Seattle may not be that self-explanatory. So let’s compare Seattle’s climate to that of several other cities in the US.
First, let’s compare Seattle to Washington state cities east of the city that experience a rain shadow effect that dramatically reduces the amount of precipitation annually recorded there.
Seattle gets 2,170 sunshine hours a year.
For Yakima, this number is 2,351. That’s almost 200 hours more of sunshine a year.
For Spokane, that number is even higher, at 2,575 hours of sunshine. Despite having four distinct seasons (with much lower average temperatures in the winter), Spokane offers many more sunny days. However, during the winter months Spokane is similarly cloudy to Seattle.
Now, let’s leave Washington state and compare Seattle to some cities on or near the Pacific Ocean.
Vancouver gets only 1,938 hours of sun, meaning it’s noticeably cloudier than Seattle. Portland gets 2,341 hours of sunshine. San Francisco gets 3,062.
And how does Seattle stack up compared to some cities on the east coast? All are much sunnier.
New York has 2,535 hours of sunshine. Philadelphia gets 2,498. Boston gets 2,634.
And as a fun fact, compared to the sunniest city in Arizona, Yuma, Seattle gets roughly half the amount of sunshine (Yuma has 4,015 hours of sun).
How Much Rain Does Seattle Get a Year?
The Pacific Northwest is known as a rainy place. But how rainy is it in reality?
To figure out how many days of bad weather a given place gets, we may also look at the number of rainy days. Of course, a precipitation day doesn’t mean a day during which it rains the entire day. It may only rain for an hour or two and later the skies may brighten. But still, it’s another useful metric to get a rough picture of the city’s average weather.
So, does it rain a lot in Seattle? Here’s precipitation data for each month of the year:
Month | Rainy days |
---|---|
January | 18.7 |
February | 15.9 |
March | 17.1 |
April | 15 |
May | 11.3 |
June | 9.2 |
July | 4.7 |
August | 4.9 |
September | 8.3 |
October | 14.3 |
November | 18.4 |
December | 18.4 |
Seattle gets on average 156 days of rain, meaning that it doesn’t rain 209 days of the year. Seattle records a little over 39 inches of rainfall a year.
While Seattle doesn’t have super dry summers, they city receives much less rain than in the wettest season between October and April.
Further Reading
If you’re curious about cities with the best climate in Washington state, check out my article on the warmest cities in Washington. You may also want to read my article What Are the Warmest Cities in the Pacific Northwest?