St. Johns, AZ 85936 Frost Dates
Frost dates for St. Johns, AZ, ZIP 85936
Around 05/02 is the usual last spring frost, about 247 days away. The first fall frost typically arrives around 10/14, about 164 frost-free days later.
St. Johns sits in USDA Zone 6b (-5 to 0°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 6b around St. Johns has about 7 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
05/02 is the middle of 30 years of NOAA records, not a promise. Plant by 04/18 and you're betting against frost in roughly 9 years out of 10. 05/17 is the safer bet, historically only a 1-in-10 chance of frost that late.
How St. Johns compares
About 164 days separate St. Johns's last and first frost, putting it 30,941 of 40,283 ZIP codes nationally. Within AZ, it ranks 448 of 506.
Learn more
the frost range explains how to read the range around St. Johns's dates instead of trusting one, and local microclimates explains what one yard in St. Johns can differ from the 85936 normal.