St. Johns, AZ 85924 Frost Dates
85924, near St. Johns, AZ: the frost window
Typically, the last spring freeze lands around 05/02, roughly 247 days out. Fall's first freeze usually shows up around 10/14, roughly 164 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts St. Johns in Zone 7a (0 to 5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
St. Johns's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
05/02 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/18 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/17 and only about 1 year in 10 sees frost after that.
St. Johns against the rest of the dataset
About 164 days separate St. Johns's last and first frost, putting it 30,940 of 40,283 ZIP codes nationally. Within AZ, it ranks 447 of 506.
Learn more
Two guides worth reading on 85924: the frost range, on how to read the range around St. Johns's dates instead of trusting one, and local microclimates, on what one yard in St. Johns can differ from the 85924 normal.