Illinois, Climate Division 9 18-Month Period Ending in March Average Temperature
Degrees Fahrenheit
1901-1977
-99
189703
50.9
0.1
189803
51.5
0.7
189903
50.1
-0.7
190003
49.4
-1.4
190103
51.3
0.5
190203
50.1
-0.7
190303
50.1
-0.7
190403
50.0
-0.8
190503
48.0
-2.8
190603
49.4
-1.4
190703
51.2
0.4
190803
50.6
-0.2
190903
51.5
0.7
191003
51.2
0.4
191103
50.6
-0.2
191203
50.0
-0.8
191303
49.3
-1.5
191403
51.5
0.7
191503
51.1
0.3
191603
50.4
-0.4
191703
51.0
0.2
191803
48.6
-2.2
191903
50.0
-0.8
192003
51.6
0.8
192103
51.2
0.4
192203
53.2
2.4
192303
52.1
1.3
192403
50.7
-0.1
192503
50.4
-0.4
192603
51.6
0.8
192703
50.4
-0.4
192803
51.0
0.2
192903
50.5
-0.3
193003
50.5
-0.3
193103
51.4
0.6
193203
53.1
2.3
193303
53.0
2.2
193403
51.7
0.9
193503
52.7
1.9
193603
50.6
-0.2
193703
50.8
0.0
193803
51.1
0.3
193903
52.4
1.6
194003
51.0
0.2
194103
49.8
-1.0
194203
52.3
1.5
194303
51.4
0.6
194403
51.0
0.2
194503
51.3
0.5
194603
50.9
0.1
194703
51.1
0.3
194803
50.6
-0.2
194903
51.2
0.4
195003
51.9
1.1
195103
50.2
-0.6
195203
49.9
-0.9
195303
51.8
1.0
195403
52.4
1.6
195503
52.4
1.6
195603
51.3
0.5
195703
51.0
0.2
195803
50.5
-0.3
195903
49.3
-1.5
196003
49.9
-0.9
196103
49.7
-1.1
196203
49.6
-1.2
196303
49.7
-1.1
196403
49.8
-1.0
196503
50.5
-0.3
196603
50.7
-0.1
196703
50.5
-0.3
196803
49.5
-1.3
196903
49.4
-1.4
197003
48.8
-2.0
197103
49.6
-1.2
197203
51.0
0.2
197303
51.4
0.6
197403
51.5
0.7
197503
51.0
0.2
197603
51.5
0.7
197703
49.2
-1.6