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 43402
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 43402 in zone 6b (the coldest night of a typical year: -5 to 0°F).
The nearest station, Bowling Green, OH, is 3 miles from the ZIP's center: its last spring frost comes after April 22 in half of years and after May 7 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 |
|---|---|---|---|---|---|---|
| Bowling Green, OHBowling Green Wastewater Treatment Plant | 3 mi | 675 ft | April 22 | May 7 | October 25 | 6b |
| Toledo Metcalf Field, OH | 14 mi | 622 ft | April 20 | May 7 | October 27 | 6b |
| Toledo, OHToledo Express Airport | 15 mi | 669 ft | April 22 | May 7 | October 24 | 6a |
| Hoytville, OH2 mi NE | 15 mi | 700 ft | April 24 | May 10 | October 21 | 6a |
| Napoleon, OH | 24 mi | 682 ft | April 24 | May 7 | October 21 | – |
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 Bowling Green
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 16 | May 7 | May 1 | April 19 | October 13 | September 30 |
| 32°F | May 7 | April 29 | April 22 | April 8 | October 25 | October 12 |
| 28°F (hard freeze) | April 25 | April 17 | April 11 | March 28 | November 5 | October 22 |
| 24°F | April 13 | April 4 | March 31 | March 15 | November 16 | November 1 |
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.