April 1947 - March 1952 Illinois Divisional Average Temperature Degrees Fahrenheit -99 1901-2000 base period 1901-2000 1101 Illinois CD 1. Northwest 47.7 24 48.2 -0.5 1102 Illinois CD 2. Northeast 47.9 20 48.4 -0.5 1103 Illinois CD 3. West 50.9 35 51.2 -0.3 1104 Illinois CD 4. Central 50.5 42 50.7 -0.2 1105 Illinois CD 5. East 50.2 47 50.3 -0.1 1106 Illinois CD 6. West Southwest 52.9 38 53.1 -0.2 1107 Illinois CD 7. East Southeast 53.0 52 53 -0.0 1108 Illinois CD 8. Southwest 55.1 38 55.3 -0.2 1109 Illinois CD 9. Southeast 55.2 36 55.4 -0.2