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 53406
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 53406 in zone 5b (the coldest night of a typical year: -15 to -10°F).
The nearest station, Racine, WI, is 3 miles from the ZIP's center: its last spring frost comes after April 24 in half of years and after May 10 in one year in ten. By the USDA's method its plant hardiness zone is 6a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Racine, WIRacine Batten Airport | 3 mi | 674 ft | April 24 | May 10 | October 24 | 6a |
| Racine station, WI | 5 mi | 595 ft | April 20 | May 6 | October 24 | 6a |
| Union Grove, WI | 9 mi | 730 ft | May 5 | May 20 | October 8 | 5b |
| Kenosha, WIKenosha Regional Airport | 10 mi | 743 ft | April 28 | May 13 | October 19 | 5b |
| South Milwaukee, WISouth Milwaukee Wastewater Treatment Plant | 12 mi | 650 ft | April 22 | May 8 | October 26 | – |
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 Racine
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 23 | May 15 | May 7 | April 23 | October 13 | September 30 |
| 32°F | May 10 | April 30 | April 24 | April 11 | October 24 | October 10 |
| 28°F (hard freeze) | April 25 | April 17 | April 11 | March 30 | November 4 | October 23 |
| 24°F | April 14 | April 5 | April 1 | March 17 | November 14 | November 2 |
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.