The Frost Atlas
the United States, drawn by its weather stations: 2697 official points of the 30-year climate record. Colour is the length of the frost-free season. Tap any station for its dates.
Dots placed by true station coordinates; no basemap needed, the record draws the country. Source: NOAA NCEI U.S. Climate Normals.
The record's extremes
365 days
Kofa Mine, AZ
63 days
Moose 1 Nne Crn, WY
December 31
Camarillo Ap, CA
January 1
Morgan City, LA
Mean dates over the 30-year normal period; individual years vary widely. National average frost-free season: about 182 days.
Reading the Atlas
Where is the longest growing season in the United States?
In the official 30-year record, Kofa Mine holds the longest mean frost-free season at 365 days. The national average across 2618 stations with frost normals is about 182 days.
Where is the shortest growing season in the United States?
Moose 1 Nne Crn records a mean frost-free season of just 63 days. At stations like this, frost can arrive in any month and season extension is the difference between a garden and none.
What am I looking at?
Every dot is one of 2697 official NOAA weather stations, placed by its real coordinates; together they trace the inhabited shape of the country. Colour is the length of the mean frost-free season. Tap a dot for that station's frost dates and winter tire windows, then send them to your calendar.