Red Oak, IA 51591 Frost Dates
When can you plant in Red Oak, IA?
Typically, the last spring freeze lands around 04/24, roughly 239 days out. The first fall frost typically arrives around 10/13, about 169 frost-free days later.
The USDA Plant Hardiness Zone Map puts Red Oak in Zone 5b (-15 to -10°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
About 7 weeks of growing season left in Red Oak before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
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
At roughly 169 frost-free days, Red Oak places 29,410 of 40,283 ZIP codes in this dataset. Within IA, it ranks 331 of 1,042.
Learn more
local microclimates covers what one yard in Red Oak can differ from the 51591 normal. zone vs. frost date covers why Zone 5b and Red Oak's frost date answer different questions.