The Climate of Seattle

Seattle has a temperate, maritime climate due to its close proximity to the Pacific Ocean. The weather is also strongly influenced by the nearby mountain ranges. Washington State is generally moist and mild on the west side of the Cascade Mountains, where Seattle is located, and dry and less temperate on the east side. Mild temperatures are prevalent year around in Seattle. Temperatures rarely get very cold in the winter or very hot in the summer. During the fall and winter, powerful storms often blow in off the ocean, bringing strong winds and drenching rains to the Puget Sound region. The mountains, especially the Olympics to the west of Seattle, receive the brunt of these storms; some rain forests on the southwestern side of the Olympics get over 200 inches of rain every year. The rain shadow effect is pronounced on the eastern slopes of the Olympics. Sequim, on the northeastern edge of the range only receives about 16 inches of rain a year.

Seattle is known for being a rainy city, and the reputation is well earned. Even though the yearly precipitation totals are not very impressive compared to many other cities, Seattle has a higher number of rainy days every year than any other major city in the continental United States. Annual precipitation is 36.2 inches; in comparison, New York City receives 40.3 inches. Often the rain is barely more than a drizzle, but will last for much of the day. Seattle also endures more overcast days than any other major city in the U.S.

The rainy season often begins around mid-October. Any day from Halloween to Easter, it's a good idea to carry an umbrella. Even with all of the precipitation in the winter months, Seattle gets very little snow. During a typical year, accumulating snow will fall less than three times. The temperature fails to reach freezing about two days a year on average. Every few years, a cold snap will plunge Western Washington below freezing for several days in a row, but such freezes rarely last for more than three of four days.

Spring in Seattle tends to be balmy, with considerably less storminess than winter. Rain is still a common occurrence, but the cloudiness is less oppressive as the sun usually returns before too long. Many flowers begin blooming as early as late February or early March.

If there is any time to be in Seattle, it is definitely the summertime. The city enjoys one of the most pleasant climates in the U.S. from June through September. Sunshine is the rule, with most days between 70 and 85 degrees. If an onshore sea breeze is blowing, the morning may start off foggy, but the sky usually clears by early afternoon at the latest. On the other hand, if a light offshore wind is blowing from the east, not a cloud may be seen and temperatures may ascend well into the 80s. Occasionally, a strong high pressure system causes temperatures to reach the 90s, but this usually only happens once a summer.