Sloan, IA 51055 Frost Dates
51055, near Sloan, IA: the frost window
The last spring frost here typically falls around 05/01, about 246 days from today. Fall's first freeze usually shows up around 10/03, roughly 154 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 Sloan, not a forecast for this year.
Stretching the season past the first frost
Sloan'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.
Why 05/01 isn't a guarantee
05/01 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/19 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/13 and only about 1 year in 10 sees frost after that.
Sloan against the rest of the dataset
About 154 days separate Sloan's last and first frost, putting it 34,375 of 40,283 ZIP codes nationally. Within IA, it ranks 899 of 1,042.
Learn more
Two guides worth reading on 51055: local microclimates, on what one yard in Sloan can differ from the 51055 normal, and zone vs. frost date, on why Zone 5a and Sloan's frost date answer different questions.