Sanborn, ND 58480 Frost Dates
Frost dates for Sanborn, ND, ZIP 58480
Around 05/13 is the usual last spring frost, about 258 days away. The first fall frost typically arrives around 09/26, about 136 frost-free days later.
Sanborn 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.
What to do before the first frost
Zone 4a around Sanborn 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
05/13 is the middle of 30 years of NOAA records, not a promise. Plant by 05/02 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 Sanborn compares
About 136 days separate Sanborn's last and first frost, putting it 37,799 of 40,283 ZIP codes nationally. Within ND, it ranks 243 of 405.
Learn more
local microclimates explains what one yard in Sanborn can differ from the 58480 normal, and zone vs. frost date explains why Zone 4a and Sanborn's frost date answer different questions.