FrostDateCheck

Stanley, IA 50671 Frost Dates

50671, near Stanley, IA: the frost window

Zone 5a

Around 04/27 is the usual last spring frost, about 242 days away. Fall's first freeze usually shows up around 10/13, roughly 169 days after the last spring frost.

The USDA Plant Hardiness Zone Map puts Stanley in Zone 5a (-20 to -15°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

Stanley'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.

How much risk comes with planting early here

04/27 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 05/10 and only about 1 year in 10 sees frost after that.

Stanley against the rest of the dataset

At roughly 169 frost-free days, Stanley places 29,628 of 40,283 ZIP codes in this dataset. Within IA, it ranks 361 of 1,042.

Learn more

Two guides worth reading on 50671: local microclimates, on what one yard in Stanley can differ from the 50671 normal, and zone vs. frost date, on why Zone 5a and Stanley's frost date answer different questions.