South Tucson, AZ 85735 Frost Dates
85735, near South Tucson, AZ: the frost window
Typically, the last spring freeze lands around 02/08, roughly 164 days out. Fall's first freeze usually shows up around 12/10, roughly 303 days after the last spring frost.
South Tucson sits in USDA Zone 9a (20 to 25°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
South Tucson's growing season runs out in roughly 15 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
02/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/06 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/08 and only about 1 year in 10 sees frost after that.
South Tucson against the rest of the dataset
About 303 days separate South Tucson's last and first frost, putting it 3,787 of 40,283 ZIP codes nationally. Within AZ, it ranks 254 of 506.
Learn more
Two guides worth reading on 85735: zone vs. frost date, on why Zone 9a 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.