Ankeny, IA 50369 Frost Dates
50369, near Ankeny, IA: the frost window
Typically, the last spring freeze lands around 04/23, roughly 238 days out. Fall's first freeze usually shows up around 10/15, roughly 173 days after the last spring frost.
Ankeny 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.
Stretching the season past the first frost
Ankeny's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/23 isn't a guarantee
04/23 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/08 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/06 and only about 1 year in 10 sees frost after that.
Ankeny against the rest of the dataset
At roughly 173 frost-free days, Ankeny places 27,716 of 40,283 ZIP codes in this dataset. Within IA, it ranks 242 of 1,042.
Learn more
Two guides worth reading on 50369: local microclimates, on what one yard in Ankeny can differ from the 50369 normal, and zone vs. frost date, on why Zone 5b and Ankeny's frost date answer different questions.