Olin, IA 52320 Frost Dates
Frost dates for Olin, IA, ZIP 52320
Typically, the last spring freeze lands around 04/27, roughly 242 days out. The first fall frost typically arrives around 10/13, about 170 frost-free days later.
Olin sits in USDA Zone 5a (-20 to -15°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 5a around Olin 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.
The actual range around Olin's last frost
04/27 is the middle of 30 years of NOAA records, not a promise. Plant by 04/12 and you're betting against frost in roughly 9 years out of 10. 05/10 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Olin compares
About 170 days separate Olin's last and first frost, putting it 29,166 of 40,283 ZIP codes nationally. Within IA, it ranks 310 of 1,042.
Learn more
local microclimates explains what one yard in Olin can differ from the 52320 normal, and zone vs. frost date explains why Zone 5a and Olin's frost date answer different questions.