Osnabrock, ND 58269 Frost Dates
Frost dates for Osnabrock, ND, ZIP 58269
Typically, the last spring freeze lands around 05/15, roughly 260 days out. The first fall frost typically arrives around 09/22, about 128 frost-free days later.
Zone 3b (-35 to -30°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 Osnabrock, not a forecast for this year.
What to do before the first frost
Zone 3b around Osnabrock 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.
The actual range around Osnabrock's last frost
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 05/04 and you're betting against frost in roughly 9 years out of 10. 05/31 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Osnabrock compares
Osnabrock's growing season runs about 128 days, ranking 38,590 of 40,283 US ZIP codes measured here, longest to shortest. Within ND, it ranks 327 of 405.
Learn more
zone vs. frost date explains why Zone 3b and Osnabrock's frost date answer different questions, and the frost range explains how to read the range around Osnabrock's dates instead of trusting one.