The Home Almanac

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

Winter tire dates for Denver

Computed from the 30-year climate record at Ralston Rsvr, the official NOAA station 23 km from Denver, Colorado.

Tires on by November 5 Mean daily temp settles below 45F
Off after March 30 Mean daily temp back above 45F
Last spring frost May 3 Planting dates for Denver

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

The climate record behind these dates

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

JanFebMarAprMayJunJulAugSepOctNovDec
343442485768747264524134

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

Winter tires and the law

No state or federal mandate

The United States has no winter-tire law: the dates above are a climate recommendation, not a legal requirement. A few mountain states enforce seasonal traction or chain requirements on specific highways and passes during winter storms. Those are road- and condition-specific, so check your state department of transportation before mountain travel in winter.

Denver winter tire questions

When should winter tires go on in Denver?

Around November 5. That is when the mean daily temperature at Ralston Rsvr, the official station nearest Denver, 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 Denver?

After March 30, 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 Denver?

There is no federal winter-tire law in the United States, and most states do not mandate them. A handful of mountain states enforce seasonal traction or chain requirements on specific highways and passes during winter storms. Those are road- and condition-specific, not a blanket rule for your city, so check your state department of transportation before mountain travel.

How are these dates calculated?

From NOAA NCEI U.S. Climate Normals 30-year climate normals at Ralston Rsvr (23 km from Denver): 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 the NOAA NCEI U.S. Climate Normals at Ralston Rsvr, 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 weeks before acting.

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