Winnett, MT 59087 Frost Dates
Winnett, MT: when does the frost end?
The last spring frost here typically falls around 05/16, about 261 days from today. Fall's first freeze usually shows up around 09/28, roughly 132 days after the last spring frost.
Winnett sits in USDA Zone 4b (-25 to -20°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
With roughly 4 weeks until Winnett's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/16 isn't a guarantee
05/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/03 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/31 and only about 1 year in 10 sees frost after that.
Winnett against the rest of the dataset
At roughly 132 frost-free days, Winnett places 38,229 of 40,283 ZIP codes in this dataset. Within MT, it ranks 126 of 392.
Learn more
Before leaning on 59087's figures: local microclimates explains what one yard in Winnett can differ from the 59087 normal, while zone vs. frost date explains why Zone 4b and Winnett's frost date answer different questions.