Seattle WA Weather by Month, Season by Season
November Through January: Peak Rain Season
Come prepared for the wettest stretch of the year. November is especially soggy, and Seattle averages more rain that month than any other US city with more than 250,000 residents. Plan on gray skies, frequent showers and the occasional foggy morning.
Days run short as well. In early November, normal highs at the airport sit around 55°F with lows near 43°F, and the sun sets before 5 p.m. Cold snaps are possible by midwinter, though the harshest Arctic air usually gets funneled east of the Cascades instead of across the Puget Sound lowland.
February and March: Wet, With a Chance of Snow
Rain keeps falling through the end of the cool season, which runs into March. Snow is most likely in winter, and the city usually sees at least a light dusting each year. Heavy snow is rare, but when it arrives it can upend plans, so keep an eye on the forecast if you travel in these months.
April and May: Drizzle Eases Off
Spring brings frequent but lighter rain. Outside the heavy winter months, drizzle and light showers are the usual form of precipitation. Snow occasionally shows up in early spring, though it is the exception.
June Through September: The Dry Season
Summer is when Seattle turns its rainy reputation on its head. From June to September, the city records some of the lowest rainfall totals of any large US city. July and August together average less than 1.6 inches of rain, and long dry runs happen; in 2017, no measurable rain fell from June 18 to August 13.
Most summer days are warm rather than hot, perfect for being outside. Heat waves are rare, but they have grown more intense this century, and the all-time record of 108°F came on June 28, 2021, after hot, compressed winds descended from the Cascades.
October: The Return of the Rain
October brings the storm track back and opens the wet season. It can also deliver a real downpour: the single wettest day on record, October 20, 2003, dropped 5.02 inches, nearly two inches more than any other day.
Rainy Days Versus Total Rainfall
Seattle's reputation comes from how often it rains, not how much. Measurable precipitation falls on about 150 days in an average year, which places the city among the five rainiest major US cities by number of wet days.
Yet the annual total averages only 39.3 inches. Because so much of it arrives as light drizzle, Seattle actually collects less rain overall than New York City, Miami or Houston. For you as a visitor, that means plenty of damp, gray days but relatively few true soakers.
Snow, Heat and Other Extremes
Seattle generally sidesteps dramatic weather. Thunder is reported on only about seven days a year, so lightning storms rarely factor into your plans. Snowfall averages 6.3 inches per year at Sea-Tac Airport, though totals swing widely from one winter to the next.
- Hottest day: 108°F on June 28, 2021
- Coldest day: 0°F on January 31, 1950
- Biggest snow day: 21.5 inches on February 2, 1916
- Wettest day: 5.02 inches on October 20, 2003
El Niño winters often run drier than normal around Puget Sound, though the 2015 to 2016 event brought extra rain instead. If you are coming to ski, note that a thin mountain snowpack in those years can mean weaker conditions.
What to Pack for Each Season
Because temperature swings are modest, packing comes down mostly to rain gear and layers. Keep these guidelines in mind:
- October through March: bring a waterproof jacket with a hood, water-resistant shoes and warm mid-layers for chilly, damp days. Locals often skip umbrellas in light drizzle, but a compact one helps during heavier winter rain.
- April and May: pack a light rain shell plus a sweater or fleece you can add or remove as showers come and go.
- June through September: reach for warm-weather clothes, sunglasses and sunscreen, with a light layer for cooler evenings near the water. Pack for heat, too, in case a rare hot spell arrives.
Spend the dry summer months soaking up Seattle's parks and waterfront views, and use the wet season as a good excuse to explore indoor things to do in Seattle.
How Nearby Areas Compare
Seattle sits in the rain shadow of the Olympic Mountains, which rise to nearly 8,000 feet about 60 miles west. Those peaks wring moisture out of Pacific storms before they reach the city. On the range's western side, the Hoh Rainforest averages around 142 inches a year.
Olympia, about 60 miles south of Seattle, lies outside that rain shadow and averages roughly 50 inches annually. If your trip includes stops beyond the city, expect conditions to change noticeably from place to place.
One detail is worth knowing before you go: Seattle's official readings come from Sea-Tac Airport, which is not inside city limits. Downtown tends to run a little warmer and drier, so conditions as you wander central Seattle neighborhoods may differ slightly from the official numbers.
Check Current Conditions Before You Go
Normals describe the typical year, but any given week can surprise you. Browse monthly normals, charts and historical data from the National Weather Service on its Seattle climate data portal and its Western Washington climate charts. For yesterday's temperatures, rainfall and sunrise times at the airport, head to the daily climate report for Sea-Tac.
