Tucson, AZ 85708 Frost Dates
85708, near Tucson, AZ: the frost window
Around 01/20 is the usual last spring frost, about 145 days away. Fall's first freeze usually shows up around 12/17, roughly 332 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Tucson in Zone 9b (25 to 30°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's 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.
How much risk comes with planting early here
01/20 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/18 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/19 and only about 1 year in 10 sees frost after that.
Tucson against the rest of the dataset
About 332 days separate Tucson's last and first frost, putting it 2,858 of 40,283 ZIP codes nationally. Within AZ, it ranks 149 of 506.
Learn more
Two guides worth reading on 85708: local microclimates, on what one yard in Tucson can differ from the 85708 normal, and zone vs. frost date, on why Zone 9b and Tucson's frost date answer different questions.