Hobson, MT 59452 Frost Dates
Hobson, MT: when does the frost end?
Typically, the last spring freeze lands around 06/15, roughly 291 days out. Fall's first freeze usually shows up around 09/04, roughly 77 days after the last spring frost.
Zone 4b (-25 to -20°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Hobson, not a forecast for this year.
Stretching the season past the first frost
With roughly 1 week until Hobson's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Hobson's last frost
06/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/31 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 07/08 and only about 1 year in 10 sees frost after that.
Hobson against the rest of the dataset
Hobson's growing season runs about 77 days, ranking 40,084 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 369 of 392.
Learn more
Before leaning on 59452's figures: the frost range explains how to read the range around Hobson's dates instead of trusting one, while local microclimates explains what one yard in Hobson can differ from the 59452 normal.