Clark Fork, ID 59853 Frost Dates
59853, near Clark Fork, ID: the frost window
The last spring frost here typically falls around 05/20, about 265 days from today. Fall's first freeze usually shows up around 09/20, roughly 119 days after the last spring frost.
Clark Fork sits in USDA Zone 6a (-10 to -5°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
Clark Fork's growing season runs out in roughly 3 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/20 isn't a guarantee
05/20 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/04 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/05 and only about 1 year in 10 sees frost after that.
Clark Fork against the rest of the dataset
About 119 days separate Clark Fork's last and first frost, putting it 39,157 of 40,283 ZIP codes nationally. Within ID, it ranks 221 of 320.
Learn more
Two guides worth reading on 59853: zone vs. frost date, on why Zone 6a and Clark Fork's frost date answer different questions, and the frost range, on how to read the range around Clark Fork's dates instead of trusting one.