Marion, IA 52498 Frost Dates
Frost dates for Marion, IA, ZIP 52498
Around 04/28 is the usual last spring frost, about 243 days away. The first fall frost typically arrives around 10/12, about 166 frost-free days later.
Marion sits in USDA Zone 5b (-15 to -10°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 5b around Marion has about 6 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 Marion's last frost
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 Marion compares
At roughly 166 frost-free days, Marion places 30,291 of 40,283 ZIP codes in this dataset. Within IA, it ranks 447 of 1,042.
Learn more
zone vs. frost date explains why Zone 5b and Marion's frost date answer different questions, and the frost range explains how to read the range around Marion's dates instead of trusting one.