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 46142
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 46142 in zone 6b (the coldest night of a typical year: -5 to 0°F).
The nearest station, Indianapolis Nwfo, IN, is 8 miles from the ZIP's center: its last spring frost comes after April 12 in half of years and after April 28 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Indianapolis Nwfo, IN | 8 mi | 790 ft | April 12 | April 28 | October 27 | – |
| Indianapolis, INIndianapolis International Airport | 8 mi | 790 ft | April 15 | May 2 | October 26 | 6b |
| Beech Grove, INIndianapolis SE Side | 9 mi | 845 ft | April 20 | May 5 | October 21 | 6b |
| Franklin, INFranklin Wastewater Treatment Plant | 13 mi | 720 ft | April 20 | May 7 | October 19 | 6b |
| Indianapolis Eagle Creek Airport, IN | 15 mi | 823 ft | April 12 | April 29 | October 29 | 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 Indianapolis Nwfo
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 8 | April 30 | April 23 | April 9 | October 17 | October 5 |
| 32°F | April 28 | April 19 | April 12 | March 31 | October 27 | October 14 |
| 28°F (hard freeze) | April 16 | April 6 | April 1 | March 19 | November 5 | October 24 |
| 24°F | April 4 | March 29 | March 23 | March 10 | November 16 | November 3 |
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.