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 54304
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 54304 in zone 5b (the coldest night of a typical year: -15 to -10°F).
The nearest station, Green Bay, WI, is 2 miles from the ZIP's center: its last spring frost comes after April 30 in half of years and after May 16 in one year in ten. By the USDA's method its plant hardiness zone is 5a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Green Bay, WIGreen Bay A S International Airport | 2 mi | 682 ft | April 30 | May 16 | October 9 | 5a |
| Ashwaubenon, WIGreen Bay Weather Office | 2 mi | 682 ft | May 1 | May 16 | October 11 | – |
| Green Bay Botanical, WI | 3 mi | 694 ft | May 7 | May 22 | October 9 | – |
| Denmark, WIDenmark Wastewater Treatment Plant | 16 mi | 811 ft | May 6 | May 20 | October 12 | – |
| Brillion, WI | 23 mi | 810 ft | May 6 | May 21 | October 6 | 5b |
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 Green Bay
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 27 | May 19 | May 13 | April 29 | September 29 | September 16 |
| 32°F | May 16 | May 7 | April 30 | April 16 | October 9 | September 24 |
| 28°F (hard freeze) | May 4 | April 24 | April 17 | April 3 | October 24 | October 6 |
| 24°F | April 21 | April 12 | April 5 | March 22 | November 6 | October 21 |
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.