The Home Almanac

Vol. I, MMXXVIThe American home, in season.Across all fifty states

Winter tire dates for Seattle

Computed from the 30-year climate record at Seattle Boeing Fld, the officialNOAA station 7 km from Seattle, Washington.

Tires on byNovember 28Mean daily temp settles below 45F
Off afterFebruary 22Mean daily temp back above 45F
Last spring frostMarch 13Planting dates for Seattle

All-day events with a one-week reminder, straight from this page.

The climate record behind these dates

Mean daily temperature by month at Seattle Boeing Fld, 30-year normals. The tire windows fall where this line crosses 45F.

JanFebMarAprMayJunJulAugSepOctNovDec
434447525863676863544642

Values below 45F shown in blue: winter tire season at Seattle.

Winter tires and the law

Check route-specific rules

The dates above are climate-based planning guidance, not a statement of the law. Requirements depend on the state, road, conditions, and equipment. For example, Colorado may activate traction or chain laws on specific highways, while Alaska regulates when studded tires may be used. Check the state department of transportation for your route and current conditions.

Seattle winter tire questions

When should winter tires go on in Seattle?

Around November 28. That is when the mean daily temperature at Seattle Boeing Fld, the official station nearest Seattle, historically settles below 45F, the threshold where winter compounds outgrip all-seasons even on dry pavement. Book the swap a week or two ahead; shops fill up after the first cold snap.

When do winter tires come off in Seattle?

After February 22, when mean daily temperatures climb back above 45F to stay. Taking them off earlier risks a late cold snap; much later wears the soft compound on warm pavement.

Are winter tires required by law near Seattle?

Requirements depend on the state, road, conditions, and equipment. For example, Colorado may activate traction or chain laws on specific highways, while Alaska regulates when studded tires may be used. Check the state department of transportation for your route and current conditions.

How are these dates calculated?

From NOAA NCEI U.S. Climate Normals 30-year climate normals at Seattle Boeing Fld (7 km from Seattle): monthly mean daily temperatures anchored mid-month, linearly interpolated across the 45F threshold. They are planning averages from the official record, not forecasts. Full method on the methodology page.

How this page was made

The dates above are computed, not written: monthly mean daily temperatures from theNOAA NCEI U.S. Climate Normalsat Seattle Boeing Fld, interpolated across the 45F tire-compound threshold.Full method: data and methodology. These are planning averages from the official record, not forecasts: microclimates, valleys, and lakeshores can run a week off the station record. Watch the forecast in the shoulder weeksbefore acting.

More for Seattle: frost and planting dates. Different place? The full planner covers all 2697 stations.