Red Oak, IA 51566 Frost Dates
Frost dates for Red Oak, IA, ZIP 51566
Around 04/24 is the usual last spring frost, about 239 days away. The first fall frost typically arrives around 10/13, about 169 frost-free days later.
Red Oak sits in USDA Zone 5b (-15 to -10°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 5b around Red Oak 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.
How much risk comes with planting early here
04/24 is the middle of 30 years of NOAA records, not a promise. Plant by 04/10 and you're betting against frost in roughly 9 years out of 10. 05/08 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Red Oak compares
About 169 days separate Red Oak's last and first frost, putting it 29,409 of 40,283 ZIP codes nationally. Within IA, it ranks 330 of 1,042.
Learn more
local microclimates explains what one yard in Red Oak can differ from the 51566 normal, and zone vs. frost date explains why Zone 5b and Red Oak's frost date answer different questions.