Illinois, Climate Division 9 60-Month Period Ending in May Average Temperature
Degrees Fahrenheit
1901-1929
-99
190005
55.4
0.0
190105
55.4
0.0
190205
55.4
0.0
190305
55.2
-0.2
190405
55.0
-0.4
190505
54.7
-0.7
190605
54.5
-0.9
190705
54.6
-0.8
190805
54.5
-0.9
190905
55.1
-0.3
191005
55.5
0.1
191105
55.6
0.2
191205
55.3
-0.1
191305
55.3
-0.1
191405
55.4
0.0
191505
55.5
0.1
191605
55.5
0.1
191705
55.6
0.2
191805
55.1
-0.3
191905
55.0
-0.4
192005
54.8
-0.6
192105
55.2
-0.2
192205
55.8
0.4
192305
56.4
1.0
192405
56.1
0.7
192505
56.3
0.9
192605
55.9
0.5
192705
55.6
0.2
192805
55.4
0.0
192905
55.5
0.1