Somerton, AZ 85364 Frost Dates
Frost dates for Somerton, AZ, ZIP 85364
The last spring frost here typically falls around 01/08, about 133 days from today. The first fall frost typically arrives around 12/28, about 362 frost-free days later.
Zone 10a (30 to 35°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 Somerton, not a forecast for this year.
What to do before the first frost
Zone 10a around Somerton has about 17 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
01/08 is the middle of 30 years of NOAA records, not a promise. Plant by 02/19 and you're betting against frost in roughly 9 years out of 10. 12/17 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Somerton compares
Somerton's growing season runs about 362 days, ranking 2,071 of 40,283 US ZIP codes measured here, longest to shortest. Within AZ, it ranks 23 of 506.
Learn more
zone vs. frost date explains why Zone 10a and Somerton's frost date answer different questions, and the frost range explains how to read the range around Somerton's dates instead of trusting one.