Carter Lake, IA 68131 Frost Dates
Frost dates for Carter Lake, IA, ZIP 68131
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.
Carter Lake sits in USDA Zone 6a (-10 to -5°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
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.
How much risk comes with planting early here
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 23,157 of 40,283 ZIP codes nationally. Within IA, it ranks 42 of 1,042.
Learn more
zone vs. frost date explains why Zone 6a and Carter Lake's frost date answer different questions, and the frost range explains how to read the range around Carter Lake's dates instead of trusting one.