Oto, IA 51044 Frost Dates
Frost dates for Oto, IA, ZIP 51044
Around 05/03 is the usual last spring frost, about 248 days away. The first fall frost typically arrives around 10/01, about 151 frost-free days later.
The USDA Plant Hardiness Zone Map puts Oto 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 Oto 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.
Why 05/03 isn't a guarantee
05/03 is the middle of 30 years of NOAA records, not a promise. Plant by 04/21 and you're betting against frost in roughly 9 years out of 10. 05/16 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Oto compares
Oto's growing season runs about 151 days, ranking 35,210 of 40,283 US ZIP codes measured here, longest to shortest. Within IA, it ranks 991 of 1,042.
Learn more
the frost range explains how to read the range around Oto's dates instead of trusting one, and local microclimates explains what one yard in Oto can differ from the 51044 normal.