Ronan, MT 59824 Frost Dates
Ronan, MT: when does the frost end?
Typically, the last spring freeze lands around 05/12, roughly 257 days out. Fall's first freeze usually shows up around 10/02, roughly 142 days after the last spring frost.
Ronan sits in USDA Zone 6a (-10 to -5°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 5 weeks until Ronan's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Ronan's last frost
05/12 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/01 and only about 1 year in 10 sees frost after that.
Ronan against the rest of the dataset
At roughly 142 frost-free days, Ronan places 36,747 of 40,283 ZIP codes in this dataset. Within MT, it ranks 56 of 392.
Learn more
Before leaning on 59824's figures: the frost range explains how to read the range around Ronan's dates instead of trusting one, while local microclimates explains what one yard in Ronan can differ from the 59824 normal.