Dyersville, IA 52040 Frost Dates
When can you plant in Dyersville, IA?
Typically, the last spring freeze lands around 04/28, roughly 243 days out. The first fall frost typically arrives around 10/10, about 164 frost-free days later.
Dyersville 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 Dyersville 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 04/12 and you're betting against frost in roughly 9 years out of 10. 05/12 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Dyersville compares
Dyersville's growing season runs about 164 days, ranking 30,914 of 40,283 US ZIP codes measured here, longest to shortest. Within IA, it ranks 580 of 1,042.
Learn more
local microclimates covers what one yard in Dyersville can differ from the 52040 normal. zone vs. frost date covers why Zone 5a and Dyersville's frost date answer different questions.