Surprise, AZ 85388 Frost Dates
When can you plant in Surprise, AZ?
Typically, the last spring freeze lands around 01/20, roughly 145 days out. The first fall frost typically arrives around 12/15, about 331 frost-free days later.
Zone 9b (25 to 30°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 Surprise, not a forecast for this year.
What to do before the first frost
About 16 weeks of growing season left in Surprise before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Surprise's last frost
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. 12/23 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Surprise compares
At roughly 331 frost-free days, Surprise places 2,926 of 40,283 ZIP codes in this dataset. Within AZ, it ranks 173 of 506.
Learn more
local microclimates covers what one yard in Surprise can differ from the 85388 normal. zone vs. frost date covers why Zone 9b and Surprise's frost date answer different questions.