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 42303
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 42303 in zone 7a (the coldest night of a typical year: 0 to 5°F).
The nearest station, Calhoun, KY, is 19 miles from the ZIP's center: its last spring frost comes after April 2 in half of years and after April 20 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Calhoun, KYCalhoun Lock 2 | 19 mi | 402 ft | April 2 | April 20 | November 1 | – |
| Tell City, IN | 20 mi | 390 ft | April 5 | April 23 | November 1 | 7b |
| Cannelton, IN | 21 mi | 402 ft | April 2 | April 20 | November 7 | – |
| Newburgh, INNewburgh Lock and Dam | 21 mi | 380 ft | April 3 | April 17 | November 2 | – |
| Beaver Dam, KY | 22 mi | 400 ft | April 10 | April 29 | October 22 | – |
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 Calhoun
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) | April 30 | April 20 | April 14 | March 28 | October 23 | October 10 |
| 32°F | April 20 | April 10 | April 2 | March 17 | November 1 | October 19 |
| 28°F (hard freeze) | April 10 | March 30 | March 23 | March 4 | November 10 | October 29 |
| 24°F | March 29 | March 17 | March 9 | February 16 | November 21 | November 6 |
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.