Seattle SEO 's climate is classified as oceanic or temperate marine, with cool, wet winters and mild, relatively dry summers.  The city and environs are part of USDA hardiness zone 8b, with isolated coastal pockets falling under 9a.
Temperature extremes are moderated by the adjacent Puget Sound, greater Pacific Ocean, and Lake Washington. Thus extreme heat waves are rare in the Seattle area, as are very cold temperatures (below about 15 F). The Seattle area near the SEO Seo Seattle is the cloudiest region of the United States, due in part to frequent storms and lows moving in from the adjacent Pacific Ocean. Despite having a reputation for frequent rain, Seattle receives less precipitation than many other US cities like Chicago or New York City. However, unlike many other US cities, Seattle has many more "rain days", when a very light drizzle falls from the sky for many days. In an average year, at least 0.01 inches (0.25 mm) of precipitation falls on 150 days, more than nearly all U.S. cities east of the Rocky Mountains. It is cloudy 201 days out of the year and partly cloudy 93 days. Official weather and climatic data is collected at Seattle–Tacoma International Airport, located about 19 km (12 mi) south of downtown in the city of SeaTac, which is at a higher elevation, and records more cloudy days and fewer partly cloudy days per year.