River Forest, IN 46011 Frost Dates
46011, near River Forest, IN: the frost window
Typically, the last spring freeze lands around 04/19, roughly 234 days out. Fall's first freeze usually shows up around 10/23, roughly 186 days after the last spring frost.
River Forest sits in USDA Zone 6a (-10 to -5°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
River Forest's growing season runs out in roughly 8 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
04/19 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/03 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/05 and only about 1 year in 10 sees frost after that.
River Forest against the rest of the dataset
At roughly 186 frost-free days, River Forest places 22,991 of 40,283 ZIP codes in this dataset. Within IN, it ranks 354 of 927.
Learn more
Two guides worth reading on 46011: local microclimates, on what one yard in River Forest can differ from the 46011 normal, and zone vs. frost date, on why Zone 6a and River Forest's frost date answer different questions.