Seattle Winter 2026-27 Snow Outlook: What a Record El Niño Means for Puget Sound

NOAA is calling for a record El Niño this winter, and the seasonal outlook tilts Seattle warm. That usually means little or no lowland snow at Sea-Tac. It also describes the winter of 2018-19, right up until February. Here is what the forecasts and Seattle's own history say for property managers across King, Snohomish, and Pierce counties. The full regional analysis, with every source linked, is in our Pacific Northwest Winter 2026-27 Snow Outlook.

What the forecasts say for Puget Sound

NOAA's Climate Prediction Center puts the odds of a very strong El Niño this winter above 90% and favors above-normal temperatures west of the Rockies from November into spring. But its September 17 seasonal discussion says the coastal Pacific Northwest probabilities were "tempered a bit" because the Pacific Decadal Oscillation is negative and the usual Gulf of Alaska warm pool has shifted west, which "may allow for slightly cooler water to influence portions of the U.S. West coast." It also notes "the possibility of one or more cold air outbreaks across the northwestern quarter of the Lower 48 states."

The region's two best-known climate voices split on what that means. University of Washington's Cliff Mass argues that very strong El Niños bring near-normal Cascade snowpack and above-normal moisture, with Washington running only about 1°F above normal. Oregon's state climatologist Larry O'Neill expects most of that moisture to fall as rain. For the lowlands, the difference between those two views is the snow line, and the snow line is what turns a wet Tuesday into a shutdown.

What Seattle's own history says

Justin Shaw of Seattle Weather Blog ran the numbers for Seattle Met: of the eight strong El Niño winters since 1950, Sea-Tac recorded zero snowfall in six. The other two produced 22.9 inches in 1965-66 and the all-time record of 67.5 inches in 1968-69.

Then there is 2018-19. An El Niño winter, warm through November, December, and January, with no snow at all until Super Bowl Sunday. February 2019 finished as Seattle's snowiest February in more than a century, its coldest in 30 years, with 21 inches for the season and snow on the ground into March. Bellevue, Kirkland, Redmond, Everett, and Kent were closed for days. Nothing in the seasonal forecast that year said it was coming.

Seattle meteorologist Scott Sistek describes the worst-case setup for this winter: a record El Niño that parks a ridge over Alaska, forces arctic air south, and then runs a warm, wet storm into it. That is the December 1996 scenario, when 12 to 18 inches of snow in Seattle turned to two inches of rain and 50-degree temperatures, and carports and flat roofs failed across the region. He calls it a scenario, not a forecast. It is the scenario a commercial property has to be covered for.

What to do in October

1. Sign the contract before the first cold snap. Equipment and crews are assigned by contract. In an event week, non-contract customers wait, and in this region an event week is the whole winter.
2. Plan for ice, not inches. Freezing rain and wet, heavy snow are Puget Sound's signature events. Pre-storm anti-icing with our LEED-compliant Easy Ice Melt is what keeps a parking lot and a loading dock from bonding with ice overnight.
3. Set your trigger in writing. On high-traffic commercial sites we run zero tolerance, not a two-inch trigger. Hospitals, distribution centers, and retail cannot wait for accumulation.
4. Get the paperwork now. Certificate of insurance, ISO SN9001 certification, response-time commitment, GPS-verified service logs, and a written scope. It is what your insurer asks for after a claim, and what every RFQ asks us for before one.