Stevensville, MT 59833 Frost Dates
Stevensville, MT: when does the frost end?
Typically, the last spring freeze lands around 05/22, roughly 267 days out. Fall's first freeze usually shows up around 09/19, roughly 115 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Stevensville in Zone 5b (-15 to -10°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
With roughly 3 weeks until Stevensville's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Stevensville's last frost
05/22 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/13 and only about 1 year in 10 sees frost after that.
Stevensville against the rest of the dataset
At roughly 115 frost-free days, Stevensville places 39,314 of 40,283 ZIP codes in this dataset. Within MT, it ranks 246 of 392.
Learn more
Before leaning on 59833's figures: local microclimates explains what one yard in Stevensville can differ from the 59833 normal, while zone vs. frost date explains why Zone 5b and Stevensville's frost date answer different questions.