Indianapolis, IN 46251 Frost Dates
When can you plant in Indianapolis, IN?
Typically, the last spring freeze lands around 04/20, roughly 235 days out. The first fall frost typically arrives around 10/21, about 183 frost-free days later.
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.
What to do before the first frost
About 8 weeks of growing season left in Indianapolis before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Indianapolis's last frost
04/20 is the middle of 30 years of NOAA records, not a promise. Plant by 04/06 and you're betting against frost in roughly 9 years out of 10. 05/05 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Indianapolis compares
Indianapolis's growing season runs about 183 days, ranking 23,712 of 40,283 US ZIP codes measured here, longest to shortest. Within IN, it ranks 404 of 927.
Learn more
local microclimates covers what one yard in Indianapolis can differ from the 46251 normal. zone vs. frost date covers why Zone 6b and Indianapolis's frost date answer different questions.