Ankeny, IA 50359 Frost Dates
Frost dates for Ankeny, IA, ZIP 50359
Around 04/23 is the usual last spring frost, about 238 days away. The first fall frost typically arrives around 10/15, about 173 frost-free days later.
Zone 5b (-15 to -10°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 Ankeny, not a forecast for this year.
What to do before the first frost
Zone 5b around Ankeny 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.
How much risk comes with planting early here
04/23 is the middle of 30 years of NOAA records, not a promise. Plant by 04/08 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 Ankeny compares
Ankeny's growing season runs about 173 days, ranking 27,708 of 40,283 US ZIP codes measured here, longest to shortest. Within IA, it ranks 234 of 1,042.
Learn more
local microclimates explains what one yard in Ankeny can differ from the 50359 normal, and zone vs. frost date explains why Zone 5b and Ankeny's frost date answer different questions.