Pacific Northwest & Alaska Snow Day Predictions

This region holds both ends of the snow-tolerance scale. Lowland Seattle and Portland see snow only occasionally, have steep hills and limited equipment, and can close for an inch or two or for freezing rain. Anchorage, by contrast, plows routinely and rarely closes for snow alone.

Puget Sound and the Willamette Valley

Lowland snow usually needs cold air flowing out of the interior through mountain gaps. When it happens, temperatures are often marginal, so the difference between wet roads and an icy mess can be a degree or two. The model reduces the weight of snow falling above freezing but treats freezing rain as highly disruptive.

Alaska

Anchorage-area schools operate through conditions that would close schools almost anywhere else. Closures tend to follow unusual events — heavy wet snow, ice, extreme wind or infrastructure problems. Alaska locations use the highest snow-tolerance tier.

East of the Cascades

Interior Washington and Oregon are colder and snowier than the coast. SnowCall automatically raises the tolerance tier for locations east of the Cascade crest.

Northwest & Alaska district guides

Seattle Public Schools — Seattle, WA
Portland Public Schools (OR) — Portland, OR
Anchorage School District — Anchorage, AK

Frequently asked questions

Why can a small snowfall close Seattle schools?

Steep hills, infrequent snow, limited plowing equipment and frequent icing make even small accumulations disruptive. The model uses a low snow-tolerance threshold for western Washington and Oregon.

Is Anchorage treated differently?

Yes — Alaska uses the deep-winter tier, so it takes much more snow or much colder wind chills to move the odds.