Wilton, IA 52778 Frost Dates
When can you plant in Wilton, IA?
Around 04/18 is the usual last spring frost, about 233 days away. The first fall frost typically arrives around 10/22, about 184 frost-free days later.
Wilton 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
About 8 weeks of growing season left in Wilton before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/18 isn't a guarantee
04/18 is the middle of 30 years of NOAA records, not a promise. Plant by 04/04 and you're betting against frost in roughly 9 years out of 10. 05/02 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Wilton compares
At roughly 184 frost-free days, Wilton places 23,550 of 40,283 ZIP codes in this dataset. Within IA, it ranks 70 of 1,042.
Learn more
zone vs. frost date covers why Zone 5b and Wilton's frost date answer different questions. the frost range covers how to read the range around Wilton's dates instead of trusting one.