Columbia Falls, MT 59411 Frost Dates
Frost dates for Columbia Falls, MT, ZIP 59411
The last spring frost here typically falls around 06/03, about 279 days from today. The first fall frost typically arrives around 09/08, about 94 frost-free days later.
The USDA Plant Hardiness Zone Map puts Columbia Falls in Zone 4b (-25 to -20°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 4b around Columbia Falls has about 2 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.
How much risk comes with planting early here
06/03 is the middle of 30 years of NOAA records, not a promise. Plant by 05/19 and you're betting against frost in roughly 9 years out of 10. 06/23 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Columbia Falls compares
Columbia Falls's growing season runs about 94 days, ranking 39,823 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 329 of 392.
Learn more
zone vs. frost date explains why Zone 4b and Columbia Falls's frost date answer different questions, and the frost range explains how to read the range around Columbia Falls's dates instead of trusting one.