Elma, IA 50628 Frost Dates
Frost dates for Elma, IA, ZIP 50628
Typically, the last spring freeze lands around 05/02, roughly 247 days out. The first fall frost typically arrives around 10/05, about 155 frost-free days later.
Zone 4b (-25 to -20°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 Elma, not a forecast for this year.
What to do before the first frost
Zone 4b around Elma has about 5 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
05/02 is the middle of 30 years of NOAA records, not a promise. Plant by 04/17 and you're betting against frost in roughly 9 years out of 10. 05/14 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Elma compares
About 155 days separate Elma's last and first frost, putting it 34,081 of 40,283 ZIP codes nationally. Within IA, it ranks 876 of 1,042.
Learn more
local microclimates explains what one yard in Elma can differ from the 50628 normal, and zone vs. frost date explains why Zone 4b and Elma's frost date answer different questions.