Frost Dates for 46222 — Indianapolis, Indiana

Half of springs at Indianapolis Eagle Creek Airport, IN see their last 32°F night by April 12; only one in ten is past it by March 30, and one in ten still has one after April 29. Planting tender crops after April 19 leaves a 30% risk of a frost on them, after April 22 20%, and after April 29 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 66% of the 125 Indiana stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 29 in half of years, as early as October 16 one year in ten, and holds off past November 10 one year in ten. A hard freeze of 28°F follows 8 days later, around November 6; in spring the one-in-ten date for 28°F is April 17, 12 days before the 32°F one. The freeze-free season lasts 198 days in a typical year, longer than at 86% of the 125 Indiana stations; it reaches 217 days one year in ten and falls short of 177 one year in ten. On average 106 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 11 days longer, to about April 23, and return around October 18. Severe cold of 16°F or below comes every winter, usually between December 9 and March 1.

July is the warmest month at Indianapolis Eagle Creek Airport, IN, averaging 85°F by day and 67°F at night; January is the coldest at 36°F and 21°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 85% of years.

Warmth for growing adds up to 3,703 growing degree days a year (base 50°F), more than at 70% of the 125 Indiana stations. 36% of them (1,348) have built up by the end of June, and July adds the most, 804. Precipitation totals 40.9 inches a year, most in June (5.1") and least in February (2.1"); May to September bring 48% of it.

The nearest other station, Indianapolis, IN, 7 miles southwest of Indianapolis, has a last frost 3 days later (April 15), a first frost 3 days earlier (October 26), a season 5 days shorter.

The first measurable snow (0.1 inch or more) in Indianapolis usually arrives around November 24, and the last of the season around March 13. Those are the middle dates across the winters of 1991–2020 at Indianapolis, IN, 6.6 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 30 days after the last snow.

ZIP 46222 is 5 miles from Indianapolis Eagle Creek Airport, IN, which stands at 823 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 10 other ZIP codes share the station; its figures are presented in full for 46112 (Brownsburg). The 2023 USDA Plant Hardiness Zone Map lists ZIP 46222 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.