This page tracks the highest and lowest temperatures ever officially recorded at 94 weather stations across Illinois, United States, based on measurements dating from 1874 to 2026. Use the interactive map or the list below to see the record high and record low temperature (in Fahrenheit) for each location, along with the date each record was set.
| Location | Temperature | Record Date |
| Aledo | 113 °F (45 °C) | July 15, 1936 |
| Alton | 116 °F (47 °C) | July 21, 1946 |
| Aurora | 111 °F (44 °C) | July 14, 1936 |
| Barrington | 103 °F (39 °C) | July 10, 1974 |
| Baylis | 106 °F (41 °C) | July 24, 2012 |
| Belleville | 110 °F (43 °C) | July 14, 1954 |
| Bensenville | 104 °F (40 °C) | June 21, 1988 |
| Benton | 104 °F (40 °C) | August 1, 1980 |
| Burbank | 107 °F (42 °C) | June 1, 1934 |
| Cairo | 108 °F (42 °C) | July 7, 2012 |
| Carbondale | 113 °F (45 °C) | August 9, 1930 |
| Carlyle | 105 °F (41 °C) | July 8, 2012 |
| Carmi | 108 °F (42 °C) | June 29, 2012 |
| Casey | 102 °F (39 °C) | August 20, 1983 |
| Champaign | 109 °F (43 °C) | July 14, 1954 |
| Charleston | 110 °F (43 °C) | July 15, 1936 |
| Chenoa | 105 °F (41 °C) | July 7, 2012 |
| Chicago | 106 °F (41 °C) | July 13, 1995 |
| Chicago | 104 °F (40 °C) | July 13, 1995 |
| Danville | 112 °F (44 °C) | July 14, 1936 |
| Decatur | 113 °F (45 °C) | July 14, 1954 |
| DeKalb | 103 °F (39 °C) | August 17, 1988 |
| Dixon | 110 °F (43 °C) | July 14, 1936 |
| Du Quoin | 113 °F (45 °C) | August 9, 1930 |
| Dwight | 103 °F (39 °C) | July 14, 1995 |
| Effingham | 111 °F (44 °C) | July 15, 1936 |
| Elgin | 103 °F (39 °C) | July 1, 1910 |
| Elizabeth | 103 °F (39 °C) | July 7, 2012 |
| Fairfield | 113 °F (45 °C) | July 22, 1901 |
| Freeport | 103 °F (39 °C) | July 8, 2012 |
| Fulton | 102 °F (39 °C) | August 18, 1988 |
| Galena | 108 °F (42 °C) | July 24, 1901 |
| Galesburg | 112 °F (44 °C) | July 15, 1936 |
| Galva | 111 °F (44 °C) | July 14, 1936 |
| Geneseo | 107 °F (42 °C) | July 24, 1901 |
| Gladstone | 105 °F (41 °C) | July 1, 1938 |
| Golconda | 107 °F (42 °C) | June 29, 2012 |
| Grand Chain | 108 °F (42 °C) | September 6, 1925 |
| Harrisburg | 113 °F (45 °C) | July 13, 1936 |
| Hillsboro | 114 °F (46 °C) | July 14, 1954 |
| Hoopeston | 111 °F (44 °C) | July 14, 1936 |
| Illinois City | 102 °F (39 °C) | August 3, 1947 |
| Jacksonville | 114 °F (46 °C) | July 14, 1954 |
| Jerseyville | 112 °F (44 °C) | July 15, 1954 |
| Joliet | 104 °F (40 °C) | June 26, 1988 |
| Kankakee | 107 °F (42 °C) | August 17, 1988 |
| Kewanee | 105 °F (41 °C) | July 25, 1940 |
| La Harpe | 113 °F (45 °C) | August 9, 1934 |
| Lawrenceville | 107 °F (42 °C) | June 29, 2012 |
| Lincoln | 113 °F (45 °C) | July 15, 1936 |
| Marseilles | 102 °F (39 °C) | July 25, 2005 |
| McHenry | 101 °F (38 °C) | July 14, 1995 |
| Minonk | 111 °F (44 °C) | July 15, 1936 |
| Modoc | 112 °F (44 °C) | September 7, 1990 |
| Moline | 104 °F (40 °C) | July 7, 2012 |
| Monmouth | 110 °F (43 °C) | July 15, 1936 |
| Morris | 109 °F (43 °C) | July 14, 1936 |
| Morrison | 112 °F (44 °C) | July 14, 1936 |
| Morrisonville | 104 °F (40 °C) | August 17, 1988 |
| Mount Carroll | 108 °F (42 °C) | July 12, 1936 |
| Mount Vernon | 114 °F (46 °C) | July 14, 1936 |
| New Boston | 111 °F (44 °C) | May 24, 1939 |
| Normal | 107 °F (42 °C) | July 8, 2012 |
| Olney | 112 °F (44 °C) | July 15, 1936 |
| Ottawa | 112 °F (44 °C) | July 21, 1901 |
| Palestine | 114 °F (46 °C) | July 14, 1954 |
| Pana | 115 °F (46 °C) | July 14, 1954 |
| Paris | 109 °F (43 °C) | July 14, 1954 |
| Park Forest | 103 °F (39 °C) | August 2, 1988 |
| Paw Paw | 101 °F (38 °C) | July 11, 1966 |
| Paxton | 102 °F (39 °C) | August 18, 1988 |
| Peoria | 105 °F (41 °C) | June 25, 1988 |
| Peru | 104 °F (40 °C) | July 29, 1983 |
| Princeton | 103 °F (39 °C) | July 18, 2012 |
| Quincy | 105 °F (41 °C) | August 27, 2003 |
| Quincy | 112 °F (44 °C) | July 14, 1954 |
| Ramsey | 106 °F (41 °C) | July 26, 2012 |
| Rantoul | 109 °F (43 °C) | July 14, 1954 |
| Robinson | 108 °F (42 °C) | July 22, 1901 |
| Rock Island Arsenal | 104 °F (40 °C) | July 6, 1874 |
| Rockford | 105 °F (41 °C) | July 7, 2012 |
| Rosiclare | 107 °F (42 °C) | June 30, 2012 |
| Salem | 105 °F (41 °C) | August 20, 1983 |
| Scott Air Force Base | 110 °F (43 °C) | July 14, 1954 |
| Shelbyville | 104 °F (40 °C) | June 25, 1988 |
| Smithland | 106 °F (41 °C) | June 30, 2012 |
| Springfield | 112 °F (44 °C) | July 14, 1954 |
| Stockton | 99 °F (37 °C) | August 18, 1988 |
| Streator | 108 °F (42 °C) | July 30, 1913 |
| Tuscola | 113 °F (45 °C) | July 14, 1954 |
| Walnut | 111 °F (44 °C) | July 14, 1936 |
| Watseka | 107 °F (42 °C) | July 14, 1936 |
| White Hall | 113 °F (45 °C) | July 24, 1934 |
| Windsor | 111 °F (44 °C) | July 14, 1936 |
The highest temperature ever officially recorded in Illinois, United States was 116 °F (47 °C), set in Alton on July 21, 1946.
The lowest temperature ever officially recorded in Illinois, United States was -38 °F (-39 °C), set in Mount Carroll on January 31, 2019.
This page includes record high and low temperature data for 94 weather stations in Illinois, United States.
The record highs and lows on this page span from 1874 to 2026 and are updated whenever a new station record is set.