Fort Peck, MT 59223 Frost Dates
59223, near Fort Peck, MT: the frost window
The last spring frost here typically falls around 05/08, about 253 days from today. Fall's first freeze usually shows up around 10/01, roughly 145 days after the last spring frost.
Zone 4a (-30 to -25°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 Fort Peck, not a forecast for this year.
Stretching the season past the first frost
Fort Peck'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 Fort Peck's last frost
05/08 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 05/20 and only about 1 year in 10 sees frost after that.
Fort Peck against the rest of the dataset
At roughly 145 frost-free days, Fort Peck places 36,284 of 40,283 ZIP codes in this dataset. Within MT, it ranks 35 of 392.
Learn more
Two guides worth reading on 59223: zone vs. frost date, on why Zone 4a and Fort Peck's frost date answer different questions, and the frost range, on how to read the range around Fort Peck's dates instead of trusting one.