Frost dates · 38 cities · zones 5b–6a
Illinois frost dates, city by city
Median last spring frost across 38 Illinois cities runs from April 10 in Chicago to May 1 in Crystal Lake.
| City | Zone | Last frost median | First frost median | Season | Jan → Dec |
|---|---|---|---|---|---|
| Chicago | 6a | Apr 10 | Nov 5 | 208 d | |
| Aurora | 5b | Apr 19 | Oct 23 | 185 d | |
| Naperville | 5b | Apr 28 | Oct 16 | 169 d | |
| Joliet | 5b | Apr 19 | Oct 25 | 188 d | |
| Rockford | 5b | Apr 24 | Oct 17 | 174 d | |
| Elgin | 5b | Apr 26 | Oct 18 | 174 d | |
| Springfield | 6a | Apr 15 | Oct 22 | 188 d | |
| Peoria | 6a | Apr 16 | Oct 23 | 189 d | |
| Champaign | 6a | Apr 15 | Oct 24 | 190 d | |
| Waukegan | 6a | Apr 30 | Oct 19 | 170 d | |
| Cicero | 6a | Apr 11 | Oct 31 | 201 d | |
| Bloomington | 6a | Apr 21 | Oct 20 | 181 d | |
| Schaumburg | 5b | Apr 30 | Oct 13 | 163 d | |
| Evanston | 6a | Apr 26 | Oct 21 | 176 d | |
| Arlington Heights | 6a | Apr 19 | Oct 26 | 190 d | |
| Bolingbrook | 6a | Apr 20 | Oct 22 | 184 d | |
| Decatur | 6a | Apr 14 | Oct 24 | 192 d | |
| Palatine | 5b | Apr 25 | Oct 19 | 177 d | |
| Skokie | 6a | Apr 26 | Oct 21 | 176 d | |
| Des Plaines | 6a | Apr 16 | Oct 28 | 193 d | |
| Orland Park | 6a | Apr 20 | Oct 22 | 184 d | |
| Oak Lawn | 6a | Apr 10 | Nov 1 | 203 d | |
| Mount Prospect | 6a | Apr 19 | Oct 26 | 190 d | |
| Berwyn | 6a | Apr 11 | Oct 31 | 201 d | |
| Tinley Park | 6a | Apr 23 | Oct 20 | 179 d | |
| Wheaton | 5b | Apr 28 | Oct 16 | 169 d | |
| Normal | 6a | Apr 25 | Oct 16 | 172 d | |
| Oak Park | 6a | Apr 11 | Oct 31 | 201 d | |
| Hoffman Estates | 5b | Apr 30 | Oct 13 | 163 d | |
| Downers Grove | 6a | Apr 28 | Oct 16 | 169 d | |
| Plainfield | 5b | Apr 20 | Oct 22 | 184 d | |
| Glenview | 6a | Apr 19 | Oct 26 | 190 d | |
| Elmhurst | 6a | Apr 16 | Oct 28 | 193 d | |
| Lombard | 6a | Apr 28 | Oct 16 | 169 d | |
| Buffalo Grove | 6a | Apr 19 | Oct 26 | 190 d | |
| Moline | 5b | Apr 24 | Oct 18 | 176 d | |
| Crystal Lake | 5b | May 1 | Oct 11 | 162 d | |
| Romeoville | 6a | Apr 20 | Oct 22 | 184 d |
Medians from NOAA NCEI 1991–2020 U.S. Climate Normals at each city's nearest qualifying station; zones from the 2023 USDA Plant Hardiness Zone Map. Open a city for the 1-in-10-year dates, the station, and a planting calendar for every sauce crop.
All states →Build a plan from your ZIP →Earliest: Chicago (Apr 10) · Latest: Crystal Lake (May 1)