Columbia Falls, MT 59919 Frost Dates
59919, near Columbia Falls, MT: the frost window
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.
Zone 5b (-15 to -10°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 Columbia Falls, not a forecast for this year.
Stretching the season past the first frost
Columbia Falls's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Columbia Falls's last frost
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
About 141 days separate Columbia Falls's last and first frost, putting it 36,901 of 40,283 ZIP codes nationally. Within MT, it ranks 61 of 392.
Learn more
Two guides worth reading on 59919: the frost range, on how to read the range around Columbia Falls's dates instead of trusting one, and local microclimates, on what one yard in Columbia Falls can differ from the 59919 normal.