Frost dates in Illinois
Across 170 NOAA stations in Illinois, the average last spring frost ranges from April 2 at Cairo 3N to May 2 at Mt Carroll.
| Albion | April 4 | October 28 | 206 |
| Aledo | April 22 | October 19 | 181 |
| Alton - Melvin Price L&D | April 4 | November 5 | 214 |
| Altona | April 28 | October 12 | 165 |
| Anna 2 Nne | April 8 | October 29 | 203 |
| Antioch | April 23 | October 21 | 179 |
| Athens 4Sw | April 19 | October 19 | 181 |
| Aurora | April 19 | October 23 | 185 |
| Avon | April 22 | October 19 | 177 |
| Barrington 3Sw | April 25 | October 19 | 177 |
| Belleville Siu Rsch | April 12 | October 20 | 189 |
| Bentley | April 13 | October 22 | 191 |
| Benton 2 N | April 4 | October 28 | 206 |
| Bloomington 5W | April 21 | October 20 | 181 |
| Brookport Dam 52 | April 6 | October 27 | 203 |
| Brownstown 4 Sw | April 3 | October 24 | 202 |
| Cahokia | April 6 | October 27 | 203 |
| Cahokia St Louis Airport | April 8 | October 26 | 200 |
| Cairo 3N | April 2 | October 31 | 211 |
| Carbondale Sewage Plt | April 9 | October 22 | 195 |
| Carbondale Southern Il Airport | April 9 | October 22 | 195 |
| Carlinville | April 14 | October 21 | 188 |
| Carlyle Rsvr | April 6 | October 29 | 204 |
| Carmi 3 | April 15 | October 19 | 183 |
| Casey | April 14 | October 20 | 187 |
| Champaign 3S | April 15 | October 24 | 190 |
| Champaign 9 Sw | April 23 | October 13 | 170 |
| Champaign Willard Airport | April 19 | October 17 | 180 |
| Channahon Dresden Isl Dam | April 16 | October 26 | 191 |
| Charleston | April 15 | October 23 | 187 |
| Chenoa | April 23 | October 15 | 174 |
| Chicago Aurora Muni Airport | April 28 | October 13 | 166 |
| Chicago Botanic Garden | April 26 | October 21 | 176 |
| Chicago Midway Airport | April 11 | October 31 | 201 |
| Chicago Midway Ap 3Sw | April 10 | November 1 | 203 |
| Chicago Northerly Is | April 10 | November 5 | 208 |
| Chicago Ohare Intl Airport | April 16 | October 28 | 193 |
| Chicago Palwaukee Airport | April 19 | October 26 | 190 |
| Chicago Waukegan Rgnl Airport | April 30 | October 21 | 173 |
| Compton 1 Nw | April 27 | October 12 | 167 |
| Congerville 2Nw | April 21 | October 17 | 178 |
| Crystal Lake 4Nw | April 25 | October 22 | 179 |
| Danville | April 21 | October 20 | 181 |
| De Kalb | April 24 | October 18 | 177 |
| Decatur Airport | April 16 | October 22 | 187 |
| Decatur Wtp | April 14 | October 24 | 192 |
| Dixon 1W | April 21 | October 19 | 180 |
| Dixon Springs Agric Ctr | April 14 | October 21 | 189 |
| Du Quoin 4 Se | April 6 | October 22 | 199 |
| Dwight | April 27 | October 15 | 170 |
| Effingham 3Sw | April 13 | October 24 | 191 |
| Elgin | April 26 | October 18 | 174 |
| Elizabeth | May 1 | October 9 | 160 |
| Fairfield Radio Wfiw | April 7 | October 26 | 201 |
| Flora | April 9 | October 24 | 198 |
| Flora 5 Nw | April 10 | October 23 | 196 |
| Freeport Waste Wtp | April 26 | October 13 | 169 |
| Fulton L&D #13 | April 13 | October 26 | 195 |
| Galena | April 26 | October 15 | 170 |
| Galesburg | April 20 | October 19 | 180 |
| Galva | April 26 | October 12 | 166 |
| Geneseo | April 20 | October 20 | 180 |
| Gibson City | April 21 | October 17 | 178 |
| Gladstone Dam 18 | April 8 | October 29 | 202 |
| Golden | April 18 | October 21 | 187 |
| Grand Chain Dam 53 | April 3 | November 5 | 216 |
| Grayville | April 7 | October 25 | 201 |
| Harrisburg | April 7 | October 26 | 202 |
| Havana | April 17 | October 19 | 185 |
| Hennepin | April 18 | October 22 | 188 |
| Hennepin Wtr Trmt Plt | April 24 | October 17 | 174 |
| Hillsboro | April 13 | October 24 | 192 |
| Hoopeston | April 22 | October 19 | 180 |
| Illinois City Dam 16 | April 18 | October 24 | 188 |
| Iuka 12 Sw | April 9 | October 24 | 196 |
| Jacksonville 2 | April 17 | October 21 | 186 |
| Jacksonville 2E | April 19 | October 17 | 179 |
| Jerseyville 2 Sw | April 14 | October 19 | 187 |
| Joliet Brandon Rd Dam | April 19 | October 25 | 188 |
| Kankakee Metro Wastewater | April 19 | October 24 | 188 |
| Kaskaskia Rvr Navigation Lock | April 8 | October 30 | 202 |
| Kewanee 1 E | April 24 | October 17 | 175 |
| Knoxville | April 21 | October 20 | 181 |
| La Harpe | April 21 | October 19 | 180 |
| Lacon | April 20 | October 17 | 178 |
| Lake Villa 2Ne | April 24 | October 23 | 180 |
| Lawrenceville 2Wsw | April 12 | October 25 | 193 |
| Lawrenceville Intl Airport | April 8 | October 26 | 200 |
| Lincoln | April 20 | October 16 | 179 |
| Lisle-Morton Arboretum | April 28 | October 16 | 169 |
| Little Red School Hse | April 19 | October 22 | 183 |
| Marengo | April 28 | October 12 | 166 |
| Marseilles Lock | April 27 | October 17 | 171 |
| Mason City 4Se | April 17 | October 18 | 182 |
| Mattoon | April 11 | October 29 | 199 |
| Mattoon Coles Co Airport | April 15 | October 24 | 189 |
| Mc Henry -Wg Stratton L&D | May 1 | October 11 | 162 |
| Mcleansboro | April 11 | October 21 | 190 |
| Minonk | April 26 | October 17 | 173 |
| Moline Quad City Intl Airport | April 24 | October 18 | 176 |
| Monmouth | April 22 | October 15 | 174 |
| Monmouth 4Nw | April 22 | October 14 | 174 |
| Morris 1 Nw | April 20 | October 23 | 184 |
| Morrison | April 26 | October 13 | 167 |
| Morrisonville | April 12 | October 20 | 190 |
| Mt Carmel | April 2 | October 31 | 209 |
| Mt Carroll | May 2 | October 7 | 154 |
| Mt Vernon 3 Ne | April 11 | October 22 | 193 |
| Mundelein 4 Wsw | April 29 | October 20 | 172 |
| Nashville 1 E | April 7 | October 26 | 201 |
| Neoga 4Nw | April 16 | October 20 | 185 |
| New Boston Dam 17 | April 14 | October 24 | 190 |
| Newton | April 13 | October 22 | 190 |
| Newton 6 Sse | April 13 | October 22 | 191 |
| Normal 4Ne | April 25 | October 16 | 172 |
| Ogden | April 20 | October 21 | 182 |
| Olney 2S | April 15 | October 23 | 189 |
| Ottawa 5Sw | April 20 | October 22 | 183 |
| Palestine | April 12 | October 22 | 193 |
| Pana | April 17 | October 23 | 188 |
| Paris Stp | April 21 | October 20 | 179 |
| Park Forest | April 23 | October 20 | 179 |
| Paw Paw 2S | April 27 | October 15 | 171 |
| Paxton 2 Wsw | April 23 | October 12 | 170 |
| Peoria Gtr Peoria Airport | April 16 | October 23 | 189 |
| Perry 6 Nw | April 18 | October 15 | 179 |
| Peru | April 24 | October 18 | 176 |
| Petersburg 1E | April 13 | October 21 | 189 |
| Piper City | April 25 | October 20 | 175 |
| Pittsfield #2 | April 14 | October 21 | 189 |
| Polo 5Nw | April 29 | October 7 | 161 |
| Pontiac | April 16 | October 24 | 191 |
| Prairie City 2S | April 17 | October 22 | 185 |
| Princeton | April 22 | October 17 | 177 |
| Princeville | April 22 | October 14 | 174 |
| Quincy Dam 21 | April 8 | October 30 | 204 |
| Quincy Rgnl Airport | April 14 | October 23 | 191 |
| Ramsey | April 15 | October 19 | 185 |
| Rantoul | April 21 | October 18 | 179 |
| Rend Lake Dam | April 4 | October 27 | 204 |
| Robinson | April 13 | October 22 | 190 |
| Rochelle | April 26 | October 13 | 168 |
| Rock Island L&D 15 | April 19 | October 22 | 184 |
| Rockford Gtr Rockford Airport | April 24 | October 17 | 174 |
| Romeoville Wfo | April 20 | October 22 | 184 |
| Rosiclare 5Nw | April 19 | October 20 | 181 |
| Rushville | April 16 | October 23 | 189 |
| Salem | April 9 | October 26 | 197 |
| Shabbona 5 Nne | April 28 | October 10 | 163 |
| Shelbyville Dam | April 10 | October 24 | 195 |
| Sidell 4N | April 19 | October 19 | 181 |
| Smithland L&D | April 3 | October 30 | 207 |
| Sparta 1 W | April 12 | October 22 | 191 |
| Springfield #2 | April 15 | October 22 | 188 |
| Springfield Capital Airport | April 14 | October 20 | 187 |
| Stockton 3 Nne | April 27 | October 9 | 165 |
| Streamwood | April 30 | October 13 | 163 |
| Streator 3 Se | April 12 | October 28 | 199 |
| Sullivan 3S | April 15 | October 22 | 187 |
| Tuscola | April 15 | October 20 | 188 |
| Vandalia | April 10 | October 24 | 196 |
| Virden | April 7 | October 29 | 205 |
| Walnut | April 24 | October 14 | 172 |
| Watseka 2 Nw | April 24 | October 16 | 174 |
| Waukegan | April 30 | October 19 | 170 |
| West Chicago Dupage Airport | April 25 | October 19 | 174 |
| Wheaton 3 Se | April 27 | October 17 | 173 |
| White Hall 1 E | April 13 | October 22 | 190 |
| Winchester | April 18 | October 20 | 183 |
| Windsor | April 16 | October 22 | 187 |
Sources
- U.S. Annual/Seasonal Climate Normals, 1991 to 2020 (freeze probability dates by station), NOAA National Centers for Environmental Information, checked 1 November 2026
- Annual/Seasonal Normals 1991 to 2020 documentation, NOAA National Centers for Environmental Information, checked 1 November 2026
- 2024 Gazetteer Files, ZIP Code Tabulation Areas, US Census Bureau, checked 1 November 2026