Poplar, MT 59274 Frost Dates
Frost dates for Poplar, MT, ZIP 59274
Typically, the last spring freeze lands around 05/16, roughly 261 days out. The first fall frost typically arrives around 09/22, about 129 frost-free days later.
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.
What to do before the first frost
Zone 4a around Poplar has about 4 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.
The actual range around Poplar's last frost
05/16 is the middle of 30 years of NOAA records, not a promise. Plant by 05/02 and you're betting against frost in roughly 9 years out of 10. 05/31 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Poplar compares
About 129 days separate Poplar's last and first frost, putting it 38,475 of 40,283 ZIP codes nationally. Within MT, it ranks 138 of 392.
Learn more
zone vs. frost date explains why Zone 4a and Poplar's frost date answer different questions, and the frost range explains how to read the range around Poplar's dates instead of trusting one.