Altoona, IA 50009 Frost Dates
When can you plant in Altoona, IA?
The last spring frost here typically falls around 04/21, about 236 days from today. The first fall frost typically arrives around 10/15, about 174 frost-free days later.
Altoona sits in USDA Zone 5b (-15 to -10°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
About 7 weeks of growing season left in Altoona before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Altoona's last frost
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. 05/05 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Altoona compares
About 174 days separate Altoona's last and first frost, putting it 27,364 of 40,283 ZIP codes nationally. Within IA, it ranks 182 of 1,042.
Learn more
zone vs. frost date covers why Zone 5b and Altoona's frost date answer different questions. the frost range covers how to read the range around Altoona's dates instead of trusting one.