Hiawatha, IA 52402 Frost Dates
When can you plant in Hiawatha, IA?
Typically, the last spring freeze lands around 04/28, roughly 243 days out. The first fall frost typically arrives around 10/12, about 166 frost-free days later.
The USDA Plant Hardiness Zone Map puts Hiawatha 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 6 weeks of growing season left in Hiawatha 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
04/28 is the middle of 30 years of NOAA records, not a promise. Plant by 04/14 and you're betting against frost in roughly 9 years out of 10. 05/13 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Hiawatha compares
About 166 days separate Hiawatha's last and first frost, putting it 30,354 of 40,283 ZIP codes nationally. Within IA, it ranks 452 of 1,042.
Learn more
the frost range covers how to read the range around Hiawatha's dates instead of trusting one. local microclimates covers what one yard in Hiawatha can differ from the 52402 normal.