Marshall, AK 99585 Frost Dates
Frost dates for Marshall, AK, ZIP 99585
Around 05/21 is the usual last spring frost, about 266 days away. The first fall frost typically arrives around 09/22, about 122 frost-free days later.
Marshall sits in USDA Zone 3b (-35 to -30°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.
What to do before the first frost
Zone 3b around Marshall has about 4 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
05/21 is the middle of 30 years of NOAA records, not a promise. Plant by 05/08 and you're betting against frost in roughly 9 years out of 10. 06/02 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Marshall compares
Marshall's growing season runs about 122 days, ranking 38,969 of 40,283 US ZIP codes measured here, longest to shortest. Within AK, it ranks 118 of 269.
Learn more
local microclimates explains what one yard in Marshall can differ from the 99585 normal, and zone vs. frost date explains why Zone 3b and Marshall's frost date answer different questions.