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 60645
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 60645 in zone 6a (the coldest night of a typical year: -10 to -5°F).
The nearest station, Chicago Botanic Garden, IL, is 10 miles from the ZIP's center: its last spring frost comes after April 26 in half of years and after May 11 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 |
|---|---|---|---|---|---|---|
| Chicago Botanic Garden, IL | 10 mi | 630 ft | April 26 | May 11 | October 21 | 6a |
| Chicago Northerly Island, IL | 11 mi | 583 ft | April 10 | April 25 | November 5 | – |
| Chicago, ILChicago O'Hare International Airport | 12 mi | 658 ft | April 16 | May 1 | October 28 | 6a |
| Wheeling, ILChicago Palwaukee Airport | 13 mi | 636 ft | April 19 | May 3 | October 26 | 6a |
| Chicago Midway Airport, IL | 16 mi | 612 ft | April 11 | April 27 | October 31 | 6a |
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 Chicago Botanic Garden
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 26 | May 16 | May 8 | April 24 | October 10 | September 28 |
| 32°F | May 11 | May 2 | April 26 | April 11 | October 21 | October 5 |
| 28°F (hard freeze) | April 28 | April 19 | April 13 | March 31 | November 1 | October 17 |
| 24°F | April 16 | April 6 | March 31 | March 15 | November 12 | 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.