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 53717
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 53717 in zone 5b (the coldest night of a typical year: -15 to -10°F).
The nearest station, Charmany Farm, WI, is 2 miles from the ZIP's center: its last spring frost comes after April 28 in half of years and after May 11 in one year in ten. By the USDA's method its plant hardiness zone is 5b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Charmany Farm, WI | 2 mi | 1,046 ft | April 28 | May 11 | October 15 | 5b |
| Uw Arboretum - Madison, WI | 5 mi | 870 ft | May 1 | May 17 | October 9 | 5a |
| Madison, WIMadison Dane County Regional Airport | 10 mi | 866 ft | May 1 | May 16 | October 10 | 5b |
| Mazomanie, WIMazomanie Wastewater Treatment Plant | 17 mi | 764 ft | May 7 | May 22 | October 1 | – |
| Sauk City, WISauk City Wastewater Treatment Plant | 17 mi | 750 ft | May 4 | May 18 | October 6 | – |
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 Charmany Farm
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 22 | May 13 | May 7 | April 25 | October 4 | September 20 |
| 32°F | May 11 | May 3 | April 28 | April 14 | October 15 | September 29 |
| 28°F (hard freeze) | May 1 | April 22 | April 17 | April 4 | October 25 | October 10 |
| 24°F | April 20 | April 12 | April 6 | March 24 | November 2 | 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.