New Vienna, IA 52065 Frost Dates
Frost dates for New Vienna, IA, ZIP 52065
Around 04/21 is the usual last spring frost, about 236 days away. The first fall frost typically arrives around 10/18, about 178 frost-free days later.
Zone 5a (-20 to -15°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 New Vienna, not a forecast for this year.
What to do before the first frost
Zone 5a around New Vienna has about 7 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 04/21 isn't a guarantee
04/21 is the middle of 30 years of NOAA records, not a promise. Plant by 04/07 and you're betting against frost in roughly 9 years out of 10. 05/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How New Vienna compares
At roughly 178 frost-free days, New Vienna places 25,888 of 40,283 ZIP codes in this dataset. Within IA, it ranks 118 of 1,042.
Learn more
zone vs. frost date explains why Zone 5a and New Vienna's frost date answer different questions, and the frost range explains how to read the range around New Vienna's dates instead of trusting one.