About Snoqualmie Pass WeatherBy Ashley Friedman; Updated September 26, 2017
Weathering the weather in the Washington Pass
Of the three passageways from east to west Washington that are kept open year-round, the Snoqualmie Pass is the lowest elevation. Still, while the pass gains less altitude than the more northern Stevens Pass and the more southern White Pass, the Snoqualmie Pass does get a tremendous amount of precipitation in the form of rain and snow throughout the year. The Snoqualmie Pass is also a popular spot for winter sports, and the area is home to many houses and chalets used as winter retreats for people living in the greater Seattle area and beyond.
Dry summers, wet winters
Summertime is the driest time of year at the Snoqualmie Pass, which makes traversing the passage easy in a car. However, temperatures do climb into the high 90s during July and August, so stay hydrated and make sure that your car's AC is functioning.
Autumn is when heavy rainfall begins, and the Snoqualmie Pass sees an average of between 4.5 and 13.5 inches of precipitation in September and October. The rains can begin suddenly without warning, and torrential downpours can go on for hours. If you're on the Pass during a heavy rainstorm, exercise extreme caution on the road, go slowly and use your high beams.
Wintertime is when the Snoqualmie Pass sees the bulk of its precipitation in the form of both snow and rain. From December until March, an average of between 75 and 104 inches of snow falls on the Pass, and between 5.4 and 8.8 inches of rain. Depending on road conditions, you may need to put chains on your tires. The Pass has designated chaining areas.
Early springtime continues to see heavy snowfall in the Snoqualmie Pass, but the precipitation begins to peter out towards April, and drops off significantly in May. As the Pass grows drier, the weather becomes more pleasant and balmy, with temperatures in March April and May remaining between the high 40s and the low 50s.
Scenic activities for all seasons
The Snoqualmie area is flanked on either side by the Cascade and the Olympic mountains, and both mountain areas offer a plethora of outdoor activities during all seasons of the year. In the autumn, the changing foliage offers a picturesque backdrop while hiking or mountain biking. In the wintertime, the area is a paradise for both downhill and cross-country skiers, as well as having trails for snowboarding, sledding and tubing. During the warmer months of the year, the trails around the mountains provide a picturesque setting for hiking and picnicking. In the summertime, enjoy camping, boating or swimming in Snoqualmie's many area lakes.
Rain is always a possibility no matter what time of year, so packing waterproof outerwear, umbrellas and rubber boots is essential. It can be chilly in the spring and autumn so it's always advisable to pack a light jacket and a sweater. In the winter, bring multiple heavy layers, including heavy wool socks and a down jacket, snow boots, gloves, hats and scarves.