Kalispell, MT 59932 Frost Dates
Frost dates for Kalispell, MT, ZIP 59932
Typically, the last spring freeze lands around 05/12, roughly 257 days out. The first fall frost typically arrives around 09/25, about 134 frost-free days later.
Zone 6a (-10 to -5°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Kalispell, not a forecast for this year.
What to do before the first frost
Zone 6a around Kalispell has about 4 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.
Why 05/12 isn't a guarantee
05/12 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 05/26 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Kalispell compares
About 134 days separate Kalispell's last and first frost, putting it 37,940 of 40,283 ZIP codes nationally. Within MT, it ranks 106 of 392.
Learn more
the frost range explains how to read the range around Kalispell's dates instead of trusting one, and local microclimates explains what one yard in Kalispell can differ from the 59932 normal.