Gutter Installation in Washington

Local know-how

Gutters and gutter guards in Washington

Western Washington outside Seattle sees long rainy seasons, fir needles and moss. Micro-mesh guards are popular.

Eastern Washington, including Spokane and the Tri-Cities, sees snow and ice in winter, and strongly attached gutters are essential.

In Spokane, winter snow and ice call for strongly attached gutters, while Bellingham, Everett and Olympia homeowners focus on micro-mesh guards for needles and moss.

Key facts: gutters in Washington

• Typical cost: HomeGuide puts seamless aluminum gutters at about $6 to $12 per linear foot installed nationally; local prices vary.
• Do gutter contractors need to register in Washington? Yes. Construction contractors must register with L&I, with a surety bond and liability insurance. Look up registrations online.
• How much rain does Seattle get? About 39.3 inches a year at Sea-Tac under the 1991–2020 normals, with measurable rain on roughly 150 days.
• Common choice: seamless aluminum K-style gutters in 5- or 6-inch sizes; 6-inch with 3x4-inch downspouts for large roofs and heavy rain.
• How to get connected: call the number on this page and you are connected with an independent local installer who serves your ZIP code. The call is free and there is no obligation.

Updated November 2026. Sources are listed at the end of this page.

Months of steady rain

Western Washington is famous for rain, but the pattern matters more than the total. Sea-Tac Airport averages about 39.3 inches of precipitation a year under NOAA’s 1991–2020 normals, with measurable precipitation on roughly 150 days; November is the wettest month at more than 6 inches, and July the driest at well under an inch. Gutters work steadily from October through April, and atmospheric rivers bring periods of very heavy rain. Eastern Washington is much drier, with cold, snowy winters in Spokane and the mountains.

Moss and needles

The Northwest’s damp, shady conditions grow roof moss, and Oregon State University Extension notes that moss holds moisture against roofing and can lift shingles. Moss washes into gutters along with Douglas fir and cedar needles, maple leaves and cones, forming a wet mat that clogs gutters and downspouts. Fine-mesh metal guards keep needles out; moss treatment on the roof reduces what washes down. See moss and gutters and gutter guards for pine needles vs. leaves.

Wind storms and falling limbs

Fall and winter wind storms bring down limbs and trees across western Washington. Strong attachment, strapped downspouts and guards that fasten down keep gutters on the house; trimming limbs over the roof prevents most damage. See gutters and high winds.

Eastern Washington snow and wildfire

Spokane, the Okanogan and the Cascades see snow and ice dams in winter and wildfire risk in summer. Close hanger spacing, heavier gauge and snow-friendly guards help in winter; metal gutters and noncombustible guards, kept clear of needles, matter in fire season. See snow load and gutters and gutters and wildfire.

Hillsides and drainage

Seattle, Tacoma and many Puget Sound communities are built on hills, and long wet winters saturate slopes. Roof water dumped onto slopes can contribute to slides. Pipe downspout water to approved drainage rather than letting it run over steep ground. See underground downspout drainage.

Planning for the wet season

Because so much rain falls between October and April, the best time for gutter work in western Washington is late summer, before the first fall storms. That is also when gutters should be cleared of the summer’s needles and cones and downspouts checked. Atmospheric rivers can drop several inches in a day, so gutters and downspouts must be clear and correctly sized going into the season. See downspout size and placement.

Washington contractor registration

Washington requires construction contractors to register with the Department of Labor & Industries (L&I), and registration requires a surety bond and general liability insurance. You can look up a contractor’s registration, bond and insurance on L&I’s website before you sign. Cities also require business licenses and set their own permit rules.

Washington areas we cover

• Seattle and Tacoma: steady rain, moss, needles, Angi cost data.
• Vancouver and Clark County are covered on our Portland page.

Costs and choices

Angi reports Seattle gutter projects averaging about $1,223, with most between about $691 and $1,757; HomeGuide puts seamless aluminum at about $6 to $12 per foot nationally. In western Washington, fine-mesh guards and enough downspouts for long wet seasons are the main priorities; in the east, snow and fire considerations. Late summer is the best time to schedule work, before the rains return. See our cost guide.

Crawl spaces and basements

Many Puget Sound homes have crawl spaces or basements, and months of rain keep soils saturated. Roof water dumped at the foundation adds to the problem, leading to damp crawl spaces, mold and wet basements. Downspouts should connect to footing-independent drain lines or discharge well away from the house where local rules allow. Never connect downspouts to the footing drain around the foundation. See wet basement? check your gutters first.

Sources

• Climate of Seattle (NOAA 1991–2020 normals, Sea-Tac Airport)
• Oregon State University Extension: How to control roof moss and prevent long-term damage
• Washington L&I: Register as a contractor
• Angi: How much does gutter installation cost in Seattle, WA?
• HomeGuide: Seamless gutters cost