West Branch, IA 52358 Frost Dates
52358, near West Branch, IA: the frost window
Typically, the last spring freeze lands around 04/29, roughly 244 days out. Fall's first freeze usually shows up around 10/09, roughly 162 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts West Branch 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
West Branch'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 West Branch's last frost
04/29 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/14 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/14 and only about 1 year in 10 sees frost after that.
West Branch against the rest of the dataset
At roughly 162 frost-free days, West Branch places 31,744 of 40,283 ZIP codes in this dataset. Within IA, it ranks 694 of 1,042.
Learn more
Two guides worth reading on 52358: zone vs. frost date, on why Zone 5b and West Branch's frost date answer different questions, and the frost range, on how to read the range around West Branch's dates instead of trusting one.