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 53204
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 53204 in zone 6a (the coldest night of a typical year: -10 to -5°F).
The nearest station, West Allis, WI, is 4 miles from the ZIP's center: its last spring frost comes after April 26 in half of years and after May 12 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| West Allis, WI | 4 mi | 723 ft | April 26 | May 12 | October 22 | – |
| Milwaukee, WIMilwaukee Mitchell Airport | 5 mi | 670 ft | April 19 | May 2 | October 29 | 6a |
| Wauwatosa, WIMount Mary College | 6 mi | 715 ft | April 26 | May 12 | October 18 | 6a |
| Hales Corners, WIHales Corners/Whitnall Park/Bo | 8 mi | 774 ft | May 3 | May 19 | October 14 | 5b |
| South Milwaukee, WISouth Milwaukee Wastewater Treatment Plant | 9 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 West Allis
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 14 | May 8 | April 23 | October 10 | September 29 |
| 32°F | May 12 | May 2 | April 26 | April 12 | October 22 | October 7 |
| 28°F (hard freeze) | April 30 | April 20 | April 14 | April 1 | November 1 | October 19 |
| 24°F | April 15 | April 7 | April 2 | March 18 | November 11 | 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.