Malcom, IA 50157 Frost Dates
50157, near Malcom, IA: the frost window
Typically, the last spring freeze lands around 05/03, roughly 248 days out. Fall's first freeze usually shows up around 10/06, roughly 155 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 Malcom, not a forecast for this year.
Stretching the season past the first frost
Malcom'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.
How much risk comes with planting early here
05/03 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 05/17 and only about 1 year in 10 sees frost after that.
Malcom against the rest of the dataset
At roughly 155 frost-free days, Malcom places 34,135 of 40,283 ZIP codes in this dataset. Within IA, it ranks 880 of 1,042.
Learn more
Two guides worth reading on 50157: the frost range, on how to read the range around Malcom's dates instead of trusting one, and local microclimates, on what one yard in Malcom can differ from the 50157 normal.