South Tucson, AZ 85745 Frost Dates
Frost dates for South Tucson, AZ, ZIP 85745
The last spring frost here typically falls around 02/11, about 167 days from today. The first fall frost typically arrives around 12/02, about 293 frost-free days later.
South 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.
What to do before the first frost
Zone 9b around South Tucson has about 14 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.
How much risk comes with planting early here
02/11 is the middle of 30 years of NOAA records, not a promise. Plant by 01/16 and you're betting against frost in roughly 9 years out of 10. 03/07 is the safer bet, historically only a 1-in-10 chance of frost that late.
How South Tucson compares
About 293 days separate South Tucson's last and first frost, putting it 4,295 of 40,283 ZIP codes nationally. Within AZ, it ranks 277 of 506.
Learn more
local microclimates explains what one yard in South Tucson can differ from the 85745 normal, and zone vs. frost date explains why Zone 9b and South Tucson's frost date answer different questions.