Shenandoah, IA 51601 Frost Dates
Frost dates for Shenandoah, IA, ZIP 51601
Typically, the last spring freeze lands around 04/20, roughly 235 days out. The first fall frost typically arrives around 10/17, about 179 frost-free days later.
The USDA Plant Hardiness Zone Map puts Shenandoah 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
Zone 5b around Shenandoah 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 Shenandoah's last frost
04/20 is the middle of 30 years of NOAA records, not a promise. Plant by 04/05 and you're betting against frost in roughly 9 years out of 10. 05/03 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Shenandoah compares
Shenandoah's growing season runs about 179 days, ranking 25,286 of 40,283 US ZIP codes measured here, longest to shortest. Within IA, it ranks 103 of 1,042.
Learn more
zone vs. frost date explains why Zone 5b and Shenandoah's frost date answer different questions, and the frost range explains how to read the range around Shenandoah's dates instead of trusting one.