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 60540
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 60540 in zone 5b (the coldest night of a typical year: -15 to -10°F).
The nearest station, Lisle, IL, is 5 miles from the ZIP's center: its last spring frost comes after April 28 in half of years and after May 14 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 |
|---|---|---|---|---|---|---|
| Lisle, ILLisle-Morton Arboretum | 5 mi | 680 ft | April 28 | May 14 | October 16 | 5b |
| Wheaton, IL3 mi SE | 5 mi | 680 ft | April 27 | May 14 | October 17 | 5b |
| Aurora, IL | 9 mi | 660 ft | April 19 | May 4 | October 23 | 5b |
| Romeoville, ILRomeoville Weather Office | 11 mi | 660 ft | April 20 | May 6 | October 22 | 5b |
| West Chicago, ILWest Chicago Dupage Airport | 12 mi | 754 ft | April 25 | May 12 | October 19 | 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 Lisle
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 25 | May 15 | May 9 | April 25 | October 6 | September 22 |
| 32°F | May 14 | May 4 | April 28 | April 14 | October 16 | October 1 |
| 28°F (hard freeze) | May 4 | April 23 | April 16 | April 2 | October 26 | October 12 |
| 24°F | April 21 | April 12 | April 5 | March 21 | November 6 | October 25 |
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.