Tucson, AZ 85749 Frost Dates
Frost dates for Tucson, AZ, ZIP 85749
Around 04/01 is the usual last spring frost, about 216 days away. The first fall frost typically arrives around 11/19, about 229 frost-free days later.
The USDA Plant Hardiness Zone Map puts Tucson in Zone 9a (20 to 25°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 9a around Tucson has about 12 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
04/01 is the middle of 30 years of NOAA records, not a promise. Plant by 03/13 and you're betting against frost in roughly 9 years out of 10. 04/21 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Tucson compares
About 229 days separate Tucson's last and first frost, putting it 10,496 of 40,283 ZIP codes nationally. Within AZ, it ranks 332 of 506.
Learn more
zone vs. frost date explains why Zone 9a and Tucson's frost date answer different questions, and the frost range explains how to read the range around Tucson's dates instead of trusting one.