Poplar, MT 59213 Frost Dates
59213, near Poplar, MT: the frost window
Typically, the last spring freeze lands around 05/24, roughly 269 days out. Fall's first freeze usually shows up around 09/14, roughly 110 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Poplar in Zone 4a (-30 to -25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Poplar's growing season runs out in roughly 2 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
05/24 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/12 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/06 and only about 1 year in 10 sees frost after that.
Poplar against the rest of the dataset
At roughly 110 frost-free days, Poplar places 39,508 of 40,283 ZIP codes in this dataset. Within MT, it ranks 276 of 392.
Learn more
Two guides worth reading on 59213: local microclimates, on what one yard in Poplar can differ from the 59213 normal, and zone vs. frost date, on why Zone 4a and Poplar's frost date answer different questions.