Athol, ID 83803 Frost Dates
83803, near Athol, ID: the frost window
The last spring frost here typically falls around 05/22, about 267 days from today. Fall's first freeze usually shows up around 09/22, roughly 122 days after the last spring frost.
Athol 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.
Stretching the season past the first frost
Athol's growing season runs out in roughly 4 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/22 isn't a guarantee
05/22 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/06 and only about 1 year in 10 sees frost after that.
Athol against the rest of the dataset
At roughly 122 frost-free days, Athol places 38,957 of 40,283 ZIP codes in this dataset. Within ID, it ranks 201 of 320.
Learn more
Two guides worth reading on 83803: local microclimates, on what one yard in Athol can differ from the 83803 normal, and zone vs. frost date, on why Zone 6b and Athol's frost date answer different questions.