South Tucson, AZ 85726 Frost Dates
85726, near South Tucson, AZ: the frost window
The last spring frost here typically falls around 01/20, about 145 days from today. Fall's first freeze usually shows up around 12/17, roughly 332 days after the last spring frost.
Zone 9b (25 to 30°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for South Tucson, not a forecast for this year.
Stretching the season past the first frost
South 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 South Tucson's last frost
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.
South Tucson against the rest of the dataset
About 332 days separate South Tucson's last and first frost, putting it 2,898 of 40,283 ZIP codes nationally. Within AZ, it ranks 157 of 506.
Learn more
Two guides worth reading on 85726: zone vs. frost date, on why Zone 9b and South Tucson's frost date answer different questions, and the frost range, on how to read the range around South Tucson's dates instead of trusting one.