Elk Horn, IA 51531 Frost Dates
51531, near Elk Horn, IA: the frost window
The last spring frost here typically falls around 04/30, about 245 days from today. Fall's first freeze usually shows up around 10/02, roughly 153 days after the last spring frost.
Zone 5a (-20 to -15°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 Elk Horn, not a forecast for this year.
Stretching the season past the first frost
Elk Horn's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
04/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/17 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/15 and only about 1 year in 10 sees frost after that.
Elk Horn against the rest of the dataset
At roughly 153 frost-free days, Elk Horn places 34,589 of 40,283 ZIP codes in this dataset. Within IA, it ranks 930 of 1,042.
Learn more
Two guides worth reading on 51531: zone vs. frost date, on why Zone 5a and Elk Horn's frost date answer different questions, and the frost range, on how to read the range around Elk Horn's dates instead of trusting one.