Harvey, IA 50256 Frost Dates
50256, near Harvey, IA: the frost window
The last spring frost here typically falls around 04/21, about 236 days from today. Fall's first freeze usually shows up around 10/16, roughly 176 days after the last spring frost.
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 Harvey, not a forecast for this year.
Stretching the season past the first frost
Harvey'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 04/21 isn't a guarantee
04/21 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 05/04 and only about 1 year in 10 sees frost after that.
Harvey against the rest of the dataset
At roughly 176 frost-free days, Harvey places 26,638 of 40,283 ZIP codes in this dataset. Within IA, it ranks 158 of 1,042.
Learn more
Two guides worth reading on 50256: the frost range, on how to read the range around Harvey's dates instead of trusting one, and local microclimates, on what one yard in Harvey can differ from the 50256 normal.