Average Monthly Sunshine in SeaTac (WA)

The graphs on this page shows the average number of hours per month and per day that SeaTac receives direct sunlight. The numbers are calculated over a 30-year period to provide a reliable average.

Monthly hours of sunshine

Sunshine in SeaTac varies greatly throughout the year. The sunniest month, July, reaches an impressive 312 hours, while December, the darkest month, offers only 54 hours. The total annual amount of sun is 2180 hours.

Daily hours of sunshine

For those who appreciate different seasons, SeaTac serves as an ideal destination. Expect longer, more sun-filled days in July with an average of 10.4 hours of sunshine daily, and embrace the darker days in December, offering only 1.8 hours of daily sunlight.

SeaTac’s total hours of sunshine compared to other major cities

SeaTac enjoys an average of 2180 hours of sunshine annually. Let’s compare this with some popular tourist destinations:

In Barcelona, Spain, there are 2530 hours of sunshine annually and is a city that can be visited year-round.

In contrast, London, UK, receives only about 1659 hours of sunshine per year, known for its frequently overcast and rainy skies.

Oslo, Norway, receives approximately 1690 hours of sunshine annually.

In Tokyo, Japan, the average annual sunshine is 1930 hours, with sunny periods between rainy seasons.

Other climate information

November, SeaTac’s wettest month, receives 14 mm of rainfall and has a maximum daytime temperature of 11°C. During the driest month July you can expect a temperature of 25°C.

For more detailed insights into the city’s temperatures, check out our Temperature page. To explore more about precipitation patterns, visit our SeaTac Precipitation page.