Tucson, AZ 85731 Frost Dates
85731, near Tucson, AZ: the frost window
The last spring frost here typically falls around 01/26, about 151 days from today. Fall's first freeze usually shows up around 12/16, roughly 326 days after the last spring frost.
Tucson sits in USDA Zone 9b (25 to 30°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Tucson's growing season runs out in roughly 16 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Tucson's last frost
01/26 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/24 and only about 1 year in 10 sees frost after that.
Tucson against the rest of the dataset
About 326 days separate Tucson's last and first frost, putting it 3,206 of 40,283 ZIP codes nationally. Within AZ, it ranks 194 of 506.
Learn more
Two guides worth reading on 85731: the frost range, on how to read the range around Tucson's dates instead of trusting one, and local microclimates, on what one yard in Tucson can differ from the 85731 normal.