Illinois, Climate Division 3 18-Month Period Ending in May Average Temperature
Degrees Fahrenheit
1901-1937
-99
189705
47.4
0.4
189805
47.6
0.6
189905
45.4
-1.6
190005
46.0
-1.0
190105
46.9
-0.1
190205
46.6
-0.4
190305
46.3
-0.7
190405
44.8
-2.2
190505
44.1
-2.9
190605
46.1
-0.9
190705
46.8
-0.2
190805
47.0
0.0
190905
47.7
0.7
191005
47.0
0.0
191105
46.9
-0.1
191205
46.3
-0.7
191305
45.7
-1.3
191405
48.3
1.3
191505
48.1
1.1
191605
46.0
-1.0
191705
45.9
-1.1
191805
44.2
-2.8
191905
46.9
-0.1
192005
47.2
0.2
192105
47.9
0.9
192205
49.9
2.9
192305
47.9
0.9
192405
46.5
-0.5
192505
46.6
-0.4
192605
46.6
-0.4
192705
46.6
-0.4
192805
47.5
0.5
192905
46.6
-0.4
193005
46.5
-0.5
193105
48.5
1.5
193205
50.2
3.2
193305
48.4
1.4
193405
48.9
1.9
193505
48.9
1.9
193605
45.7
-1.3
193705
46.8
-0.2