Pima, AZ 85531 Frost Dates
When can you plant in Pima, AZ?
Typically, the last spring freeze lands around 03/25, roughly 209 days out. The first fall frost typically arrives around 11/09, about 228 frost-free days later.
Zone 8b (15 to 20°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 Pima, not a forecast for this year.
What to do before the first frost
About 10 weeks of growing season left in Pima before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Pima's last frost
03/25 is the middle of 30 years of NOAA records, not a promise. Plant by 03/05 and you're betting against frost in roughly 9 years out of 10. 04/14 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Pima compares
Pima's growing season runs about 228 days, ranking 10,845 of 40,283 US ZIP codes measured here, longest to shortest. Within AZ, it ranks 338 of 506.
Learn more
zone vs. frost date covers why Zone 8b and Pima's frost date answer different questions. the frost range covers how to read the range around Pima's dates instead of trusting one.