Columbia Falls, MT 59926 Frost Dates
Columbia Falls, MT: when does the frost end?
The last spring frost here typically falls around 05/09, about 254 days from today. Fall's first freeze usually shows up around 10/01, roughly 141 days after the last spring frost.
Columbia Falls sits in USDA Zone 5b (-15 to -10°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
With roughly 5 weeks until Columbia Falls's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/09 isn't a guarantee
05/09 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/30 and only about 1 year in 10 sees frost after that.
Columbia Falls against the rest of the dataset
Columbia Falls's growing season runs about 141 days, ranking 36,902 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 62 of 392.
Learn more
Before leaning on 59926's figures: zone vs. frost date explains why Zone 5b and Columbia Falls's frost date answer different questions, while the frost range explains how to read the range around Columbia Falls's dates instead of trusting one.