South Tucson, AZ 85701 Frost Dates
Frost dates for South Tucson, AZ, ZIP 85701
The last spring frost here typically falls around 01/20, about 145 days from today. The first fall frost typically arrives around 12/17, about 332 frost-free days later.
The USDA Plant Hardiness Zone Map puts South 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.
What to do before the first frost
Zone 9b around South Tucson has about 16 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 01/20 isn't a guarantee
01/20 is the middle of 30 years of NOAA records, not a promise. Plant by 02/18 and you're betting against frost in roughly 9 years out of 10. 12/19 is the safer bet, historically only a 1-in-10 chance of frost that late.
How South Tucson compares
At roughly 332 frost-free days, South Tucson places 2,893 of 40,283 ZIP codes in this dataset. Within AZ, it ranks 152 of 506.
Learn more
local microclimates explains what one yard in South Tucson can differ from the 85701 normal, and zone vs. frost date explains why Zone 9b and South Tucson's frost date answer different questions.