Illinois, Climate Division 8. Southwest, Average Temperature Rankings, April 2022 1901-2000 Degrees Fahrenheit 1 54.6 55.3 -0.7 48 82 1907 1896 2020 2021 normal 1937,1943,2000 2 51.2 50.0 1.2 83 47 1960 2012 2019 2021 normal 1990,2023 3 45.2 44.9 0.3 65 65 1899 2012 2021 2020 normal 1972,2003 4 41.1 41.5 -0.4 53 77 1978 2012 2018 2021 normal 1917,1941,1983,1994 5 42.1 40.1 2.0 103 26 1978 2012 2021 2020 top-third 1955,1995 6 42.5 40.9 1.6 99 30 1912 2012 2021 2021 top-third 1972,2021 7 45.3 43.2 2.1 107 22 1899,1978 2012 2021 2017 top-third 1935,1946 8 48.5 46.5 2.0 110 19 1918 2017 2021 2020 top-third 9 51.7 49.8 1.9 112 17 1918 2017 2021 2020 top-third 1942 10 54.3 52.6 1.7 110 19 1918 2012 2021 2020 top-third 1981 11 56.2 54.5 1.7 114 15 1918 2012,2017 2021 2020 top-third 1921,1939,1974,2020 12 56.9 55.4 1.5 111 18 1918 2012,2017 2021 2020 top-third 1937,1939,1976 18 52.1 50.5 1.6 108 20 1905,1979 2017 2021 2018 top-third 2016 24 56.4 55.4 1.0 103 25 1978 2017 2019 2021 top-third 2003,2005,2019 36 56.7 55.4 1.3 110 17 1979 2018 2021 2021 top-third 1923,1939,2021 48 56.8 55.3 1.5 116 10 1980 2019 2021 2020 top-tenth 1956,1957,2007 60 56.5 55.3 1.2 109 16 1980,1981 2020 2018 2021 top-third 1934,1936,1956,2007