Broadus, MT 59345 Frost Dates
Broadus, MT: when does the frost end?
Around 05/16 is the usual last spring frost, about 261 days away. Fall's first freeze usually shows up around 09/28, roughly 135 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Broadus in Zone 4b (-25 to -20°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 4 weeks until Broadus's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
05/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/29 and only about 1 year in 10 sees frost after that.
Broadus against the rest of the dataset
At roughly 135 frost-free days, Broadus places 37,911 of 40,283 ZIP codes in this dataset. Within MT, it ranks 103 of 392.
Learn more
Before leaning on 59345's figures: local microclimates explains what one yard in Broadus can differ from the 59345 normal, while zone vs. frost date explains why Zone 4b and Broadus's frost date answer different questions.