Moore, MT 59464 Frost Dates
Moore, MT: when does the frost end?
Typically, the last spring freeze lands around 05/23, roughly 268 days out. Fall's first freeze usually shows up around 09/21, roughly 119 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 Moore, not a forecast for this year.
Stretching the season past the first frost
With roughly 3 weeks until Moore'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
05/23 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/11 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/08 and only about 1 year in 10 sees frost after that.
Moore against the rest of the dataset
Moore's growing season runs about 119 days, ranking 39,184 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 225 of 392.
Learn more
Before leaning on 59464's figures: zone vs. frost date explains why Zone 4b and Moore's frost date answer different questions, while the frost range explains how to read the range around Moore's dates instead of trusting one.