Winifred, MT 59535 Frost Dates
Frost dates for Winifred, MT, ZIP 59535
The last spring frost here typically falls around 05/23, about 268 days from today. The first fall frost typically arrives around 09/23, about 121 frost-free days later.
The USDA Plant Hardiness Zone Map puts Winifred in Zone 4b (-25 to -20°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 4b around Winifred 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.
How much risk comes with planting early here
05/23 is the middle of 30 years of NOAA records, not a promise. Plant by 05/11 and you're betting against frost in roughly 9 years out of 10. 06/03 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Winifred compares
Winifred's growing season runs about 121 days, ranking 39,055 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 211 of 392.
Learn more
zone vs. frost date explains why Zone 4b and Winifred's frost date answer different questions, and the frost range explains how to read the range around Winifred's dates instead of trusting one.