Hartley, IA 51346 Frost Dates
When can you plant in Hartley, IA?
Typically, the last spring freeze lands around 05/01, roughly 246 days out. The first fall frost typically arrives around 10/07, about 160 frost-free days later.
Hartley 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 Hartley before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Hartley's last frost
05/01 is the middle of 30 years of NOAA records, not a promise. Plant by 04/16 and you're betting against frost in roughly 9 years out of 10. 05/13 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Hartley compares
About 160 days separate Hartley's last and first frost, putting it 32,401 of 40,283 ZIP codes nationally. Within IA, it ranks 760 of 1,042.
Learn more
the frost range covers how to read the range around Hartley's dates instead of trusting one. local microclimates covers what one yard in Hartley can differ from the 51346 normal.