FrostDateCheck

Fontanelle, IA 50846 Frost Dates

50846, near Fontanelle, IA: the frost window

Zone 5b

Around 04/25 is the usual last spring frost, about 240 days away. Fall's first freeze usually shows up around 10/12, roughly 170 days after the last spring frost.

The USDA Plant Hardiness Zone Map puts Fontanelle in Zone 5b (-15 to -10°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.

Stretching the season past the first frost

Fontanelle's growing season runs out in roughly 6 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.

The actual range around Fontanelle's last frost

04/25 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/12 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/07 and only about 1 year in 10 sees frost after that.

Fontanelle against the rest of the dataset

At roughly 170 frost-free days, Fontanelle places 29,165 of 40,283 ZIP codes in this dataset. Within IA, it ranks 309 of 1,042.

Learn more

Two guides worth reading on 50846: local microclimates, on what one yard in Fontanelle can differ from the 50846 normal, and zone vs. frost date, on why Zone 5b and Fontanelle's frost date answer different questions.