Kalispell, MT 59922 Frost Dates
59922, near Kalispell, MT: the frost window
The last spring frost here typically falls around 05/01, about 246 days from today. Fall's first freeze usually shows up around 10/15, roughly 165 days after the last spring frost.
Kalispell 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
Kalispell'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.
Why 05/01 isn't a guarantee
05/01 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/16 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/16 and only about 1 year in 10 sees frost after that.
Kalispell against the rest of the dataset
Kalispell's growing season runs about 165 days, ranking 30,509 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 1 of 392.
Learn more
Two guides worth reading on 59922: zone vs. frost date, on why Zone 6a and Kalispell's frost date answer different questions, and the frost range, on how to read the range around Kalispell's dates instead of trusting one.