Underwood, ND 58576 Frost Dates
Frost dates for Underwood, ND, ZIP 58576
Typically, the last spring freeze lands around 05/10, roughly 255 days out. The first fall frost typically arrives around 09/29, about 139 frost-free days later.
The USDA Plant Hardiness Zone Map puts Underwood in Zone 4a (-30 to -25°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
Zone 4a around Underwood has about 5 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.
The actual range around Underwood's last frost
05/10 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 05/25 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Underwood compares
About 139 days separate Underwood's last and first frost, putting it 37,257 of 40,283 ZIP codes nationally. Within ND, it ranks 143 of 405.
Learn more
local microclimates explains what one yard in Underwood can differ from the 58576 normal, and zone vs. frost date explains why Zone 4a and Underwood's frost date answer different questions.