Corwith, IA 50430 Frost Dates
When can you plant in Corwith, IA?
Typically, the last spring freeze lands around 04/26, roughly 241 days out. The first fall frost typically arrives around 10/12, about 169 frost-free days later.
Zone 5a (-20 to -15°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 Corwith, not a forecast for this year.
What to do before the first frost
About 6 weeks of growing season left in Corwith before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Corwith's last frost
04/26 is the middle of 30 years of NOAA records, not a promise. Plant by 04/11 and you're betting against frost in roughly 9 years out of 10. 05/07 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Corwith compares
Corwith's growing season runs about 169 days, ranking 29,598 of 40,283 US ZIP codes measured here, longest to shortest. Within IA, it ranks 351 of 1,042.
Learn more
local microclimates covers what one yard in Corwith can differ from the 50430 normal. zone vs. frost date covers why Zone 5a and Corwith's frost date answer different questions.