Casa Grande, AZ 85147 Frost Dates
Frost dates for Casa Grande, AZ, ZIP 85147
Around 02/01 is the usual last spring frost, about 157 days away. The first fall frost typically arrives around 12/11, about 315 frost-free days later.
Zone 9a (20 to 25°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 Casa Grande, not a forecast for this year.
What to do before the first frost
Zone 9a around Casa Grande has about 15 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.
The actual range around Casa Grande's last frost
02/01 is the middle of 30 years of NOAA records, not a promise. Plant by 01/02 and you're betting against frost in roughly 9 years out of 10. 02/27 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Casa Grande compares
At roughly 315 frost-free days, Casa Grande places 3,412 of 40,283 ZIP codes in this dataset. Within AZ, it ranks 214 of 506.
Learn more
zone vs. frost date explains why Zone 9a and Casa Grande's frost date answer different questions, and the frost range explains how to read the range around Casa Grande's dates instead of trusting one.