Alta Vista, IA 50603 Frost Dates
Frost dates for Alta Vista, IA, ZIP 50603
Typically, the last spring freeze lands around 05/02, roughly 247 days out. The first fall frost typically arrives around 10/05, about 155 frost-free days later.
The USDA Plant Hardiness Zone Map puts Alta Vista in Zone 5a (-20 to -15°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 5a around Alta Vista has about 5 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
05/02 is the middle of 30 years of NOAA records, not a promise. Plant by 04/17 and you're betting against frost in roughly 9 years out of 10. 05/14 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Alta Vista compares
At roughly 155 frost-free days, Alta Vista places 34,153 of 40,283 ZIP codes in this dataset. Within IA, it ranks 885 of 1,042.
Learn more
zone vs. frost date explains why Zone 5a and Alta Vista's frost date answer different questions, and the frost range explains how to read the range around Alta Vista's dates instead of trusting one.