Altoona, WI 54720 Frost Dates
Frost dates for Altoona, WI, ZIP 54720
The last spring frost here typically falls around 04/24, about 239 days from today. The first fall frost typically arrives around 10/14, about 170 frost-free days later.
The USDA Plant Hardiness Zone Map puts Altoona in Zone 4b (-25 to -20°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 4b around Altoona 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 04/24 isn't a guarantee
04/24 is the middle of 30 years of NOAA records, not a promise. Plant by 04/09 and you're betting against frost in roughly 9 years out of 10. 05/07 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Altoona compares
About 170 days separate Altoona's last and first frost, putting it 28,948 of 40,283 ZIP codes nationally. Within WI, it ranks 121 of 860.
Learn more
zone vs. frost date explains why Zone 4b and Altoona's frost date answer different questions, and the frost range explains how to read the range around Altoona's dates instead of trusting one.