Frost dates by ZIP code: The nearest NOAA stations to your ZIP, 1991-2020 normals
Enter a five-digit ZIP code. PlainClimate finds its center (Census Bureau 2024) and the five nearest NOAA stations with frost dates, and shows each station's last spring and first autumn 32°F dates with its distance and elevation.
Frost dates near ZIP 46143
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 46143 in zone 6a (the coldest night of a typical year: -10 to -5°F).
The nearest station, Beech Grove, IN, is 9 miles from the ZIP's center: its last spring frost comes after April 20 in half of years and after May 5 in one year in ten. By the USDA's method its plant hardiness zone is 6b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Beech Grove, INIndianapolis SE Side | 9 mi | 845 ft | April 20 | May 5 | October 21 | 6b |
| Franklin, INFranklin Wastewater Treatment Plant | 10 mi | 720 ft | April 20 | May 7 | October 19 | 6b |
| Indianapolis Nwfo, IN | 12 mi | 790 ft | April 12 | April 28 | October 27 | – |
| Indianapolis, INIndianapolis International Airport | 12 mi | 790 ft | April 15 | May 2 | October 26 | 6b |
| Shelbyville, INShelbyville Municipal Airport | 17 mi | 804 ft | April 14 | April 29 | October 23 | 6b |
Frost comes later in spring at higher and colder stations and earlier in low, open ground: prefer a station at a similar elevation to yours. Hardiness zone in the table: the USDA's rule (the average of each year's coldest night, 1991-2020) applied to the station's own record.
Every frost threshold at Beech Grove
NOAA publishes the dates for several temperatures and odds. A 30% spring date means a 3-in-10 chance of a later frost (the convention almanacs use); 50% is the median; 10% the cautious date.
| Threshold | Spring, 10% | Spring, 30% | Spring, 50% | Spring, 90% | Autumn, 50% | Autumn, 10% |
|---|---|---|---|---|---|---|
| 36°F (light frost) | May 17 | May 7 | April 30 | April 16 | October 11 | September 27 |
| 32°F | May 5 | April 26 | April 20 | April 6 | October 21 | October 7 |
| 28°F (hard freeze) | April 23 | April 15 | April 7 | March 25 | November 1 | October 20 |
| 24°F | April 11 | April 2 | March 28 | March 12 | November 11 | October 30 |
Source: NOAA NCEI 1991-2020 annual normals; ZIP centers: Census Bureau 2024 Gazetteer; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. Autumn 10%: one year in ten has its first frost before this date.