Carter Lake, IA 68108 Frost Dates
Frost dates for Carter Lake, IA, ZIP 68108
Typically, the last spring freeze lands around 04/18, roughly 233 days out. The first fall frost typically arrives around 10/21, about 185 frost-free days later.
The USDA Plant Hardiness Zone Map puts Carter Lake in Zone 6a (-10 to -5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 6a around Carter Lake has about 8 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 04/18 isn't a guarantee
04/18 is the middle of 30 years of NOAA records, not a promise. Plant by 04/05 and you're betting against frost in roughly 9 years out of 10. 04/30 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Carter Lake compares
About 185 days separate Carter Lake's last and first frost, putting it 23,153 of 40,283 ZIP codes nationally. Within IA, it ranks 38 of 1,042.
Learn more
the frost range explains how to read the range around Carter Lake's dates instead of trusting one, and local microclimates explains what one yard in Carter Lake can differ from the 68108 normal.