Indianapolis, IN 46285 Frost Dates
46285, near Indianapolis, IN: the frost window
Around 04/20 is the usual last spring frost, about 235 days away. Fall's first freeze usually shows up around 10/21, roughly 183 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Indianapolis in Zone 6b (-5 to 0°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
Indianapolis'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.
The actual range around Indianapolis's last frost
04/20 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/06 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.
Indianapolis against the rest of the dataset
About 183 days separate Indianapolis's last and first frost, putting it 23,718 of 40,283 ZIP codes nationally. Within IN, it ranks 410 of 927.
Learn more
Two guides worth reading on 46285: the frost range, on how to read the range around Indianapolis's dates instead of trusting one, and local microclimates, on what one yard in Indianapolis can differ from the 46285 normal.