Granville, IA 51022 Frost Dates
When can you plant in Granville, IA?
Typically, the last spring freeze lands around 05/05, roughly 250 days out. The first fall frost typically arrives around 09/28, about 145 frost-free days later.
Granville 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 4 weeks of growing season left in Granville before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Granville's last frost
05/05 is the middle of 30 years of NOAA records, not a promise. Plant by 04/24 and you're betting against frost in roughly 9 years out of 10. 05/18 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Granville compares
At roughly 145 frost-free days, Granville places 36,274 of 40,283 ZIP codes in this dataset. Within IA, it ranks 1,041 of 1,042.
Learn more
the frost range covers how to read the range around Granville's dates instead of trusting one. local microclimates covers what one yard in Granville can differ from the 51022 normal.