Temperatures across central and southeast Illinois have reached 100 degrees an unusually high number of times so far this year. A review of climate records indicates that 1988 was the most recent year that had a comparable number of 100-degree days. However, there is still a ways to go before any records are broken for the most 100-degree days in a calendar year.
Here are some statistics for area cities through July 31.
| Location | Number of 100-degree days in 2012 |
Hottest temperature this year |
Last time it was warmer |
Top 5 years with highs >=100 degrees |
| Charleston | 14 days | 105° on June 29 and July 6 | July 19, 1954 (107°) | 1936 (26 days) 1914 (25 days) 1933 (23 days) 1934 (21 days) 1930 (20 days) |
| Decatur | 5 days | 102° on July 6 | Aug. 18, 1988 (104°) | 1936 (26 days) 1934 (23 days) 1913 and 1931 (17 days) 1930 (16 days) 1916 (14 days) |
| Jacksonville | 10 days | 105° on July 8 | July 20, 1954 (107°) | 1936 (36 days) 1934 (29 days) 1954 (18 days) 1930 (16 days) 1913 and 1931 (15 days) |
| Lincoln | 6 days | 102° on July 6 and 7 | Aug. 21, 1983 (104°) |
1936 (26 days) |
| Normal | 12 days (tied for 5th most in a calendar year) |
107° on July 8 | July 15, 1936 (114°) | 1936 (22 days) 1916 (20 days) 1934 (17 days) 1931 (15 days) 1894 (12 days) |
| Olney | 15 days (tied for 4th most in a calendar year) |
105° on June 29 and July 6 | Sep. 2, 1953 (106°) | 1936 (39 days) 1914 and 1930 (24 days) 1954 (19 days) 1901 (15 days) 1931 (14 days) |
| Palestine | 15 days (tied for 5th most in a calendar year) |
105° on July 7 | Aug. 18, 1988 (107°) | 1954 (30 days) 1936 (27 days) 1930 and 1988 (26 days) 1953 (23 days) 1913, 1933, 1934 (15 days) |
| Paris | 11 days | 105° on June 29 | July 18, 1954 (107°) | 1936 (31 days) 1913 (21 days) 1934 (14 days) 1930 (13 days) 1896 and 1988 (12 days) |
| Peoria | 8 days | 104° on July 7 and 23 | June 25, 1988 (105°) | 1936 (23 days) 1934 (18 days) 1887 (11 days) 1983 (10 days) 1912, 1930, 1931, 1988 (9 days) |
| Springfield | 11 days (3rd most in a calendar year) |
104° on July 6 and 7 | July 13, 1966 (106°) | 1936 (29 days) 1934 (18 days) 1931 (10 days) 1954 (9 days) 1966 (8 days) |
| Urbana | 9 days (3rd most in a calendar year) |
103° on July 6 and 7 | July 14, 1954 (109°) | 1936 (15 days) 1934 (11 days) 1954 (8 days) 1930 (7 days) 1988 (5 days) |
Normal number of days per year with highs of at least 100 degrees. Image courtesy of the Illinois State Water Survey.
Springfield has 25 days with high temperatures at or above 90 degrees in July 2012. This is tied for 3rd most days with 27 days in 1901, 26 days in 1916 and 25 days in 1921, 1936 and 2012.
Peoria has 24 days with high temperatures at or above 90 degrees in July 2012. This is tied for 2nd most days that warm in July with 26 days in 1887 & 1901 and 24 days in 1916 and 2012.