Saco, MT 59261 Frost Dates
When can you plant in Saco, MT?
The last spring frost here typically falls around 05/15, about 260 days from today. The first fall frost typically arrives around 09/23, about 130 frost-free days later.
The USDA Plant Hardiness Zone Map puts Saco in Zone 3b (-35 to -30°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 4 weeks of growing season left in Saco before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 05/03 and you're betting against frost in roughly 9 years out of 10. 05/26 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Saco compares
Saco's growing season runs about 130 days, ranking 38,420 of 40,283 US ZIP codes measured here, longest to shortest. Within MT, it ranks 132 of 392.
Learn more
local microclimates covers what one yard in Saco can differ from the 59261 normal. zone vs. frost date covers why Zone 3b and Saco's frost date answer different questions.