FrostDateCheck

Marion, IA 52302 Frost Dates

When can you plant in Marion, IA?

Zone 5a

The last spring frost here typically falls around 04/28, about 243 days from today. The first fall frost typically arrives around 10/12, about 166 frost-free days later.

Marion 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

About 6 weeks of growing season left in Marion before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

Why 04/28 isn't a guarantee

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

About 166 days separate Marion's last and first frost, putting it 30,284 of 40,283 ZIP codes nationally. Within IA, it ranks 440 of 1,042.

Learn more

the frost range covers how to read the range around Marion's dates instead of trusting one. local microclimates covers what one yard in Marion can differ from the 52302 normal.