Guernsey, IA 52221 Frost Dates
When can you plant in Guernsey, IA?
Typically, the last spring freeze lands around 04/28, roughly 243 days out. The first fall frost typically arrives around 10/10, about 165 frost-free days later.
Zone 5b (-15 to -10°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Guernsey, not a forecast for this year.
What to do before the first frost
About 6 weeks of growing season left in Guernsey 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. 05/11 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Guernsey compares
About 165 days separate Guernsey's last and first frost, putting it 30,789 of 40,283 ZIP codes nationally. Within IA, it ranks 570 of 1,042.
Learn more
the frost range covers how to read the range around Guernsey's dates instead of trusting one. local microclimates covers what one yard in Guernsey can differ from the 52221 normal.