Hingham, MT 59530 Frost Dates
Hingham, MT: when does the frost end?
Around 05/21 is the usual last spring frost, about 266 days away. Fall's first freeze usually shows up around 09/19, roughly 119 days after the last spring frost.
Hingham sits in USDA Zone 4a (-30 to -25°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 3 weeks until Hingham's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/21 isn't a guarantee
05/21 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/08 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/06 and only about 1 year in 10 sees frost after that.
Hingham against the rest of the dataset
At roughly 119 frost-free days, Hingham places 39,191 of 40,283 ZIP codes in this dataset. Within MT, it ranks 226 of 392.
Learn more
Before leaning on 59530's figures: local microclimates explains what one yard in Hingham can differ from the 59530 normal, while zone vs. frost date explains why Zone 4a and Hingham's frost date answer different questions.