Oelwein, IA 50662 Frost Dates
Frost dates for Oelwein, IA, ZIP 50662
Typically, the last spring freeze lands around 04/27, roughly 242 days out. The first fall frost typically arrives around 10/13, about 169 frost-free days later.
The USDA Plant Hardiness Zone Map puts Oelwein in Zone 5a (-20 to -15°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 5a around Oelwein has about 7 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.
Why 04/27 isn't a guarantee
04/27 is the middle of 30 years of NOAA records, not a promise. Plant by 04/12 and you're betting against frost in roughly 9 years out of 10. 05/10 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Oelwein compares
At roughly 169 frost-free days, Oelwein places 29,408 of 40,283 ZIP codes in this dataset. Within IA, it ranks 329 of 1,042.
Learn more
local microclimates explains what one yard in Oelwein can differ from the 50662 normal, and zone vs. frost date explains why Zone 5a and Oelwein's frost date answer different questions.