Illinois, Climate Division 9 36-Month Period Ending in May Average Temperature
Degrees Fahrenheit
1901-1939
-99
189805
55.9
0.3
189905
55.1
-0.5
190005
55.3
-0.3
190105
55.1
-0.5
190205
55.5
-0.1
190305
55.6
0.0
190405
54.6
-1.0
190505
54.2
-1.4
190605
53.8
-1.8
190705
54.7
-0.9
190805
55.3
-0.3
190905
55.7
0.1
191005
55.6
0.0
191105
55.7
0.1
191205
55.0
-0.6
191305
55.0
-0.6
191405
55.3
-0.3
191505
56.0
0.4
191605
56.0
0.4
191705
55.4
-0.2
191805
54.2
-1.4
191905
54.6
-1.0
192005
54.7
-0.9
192105
56.2
0.6
192205
56.6
1.0
192305
56.9
1.3
192405
56.1
0.5
192505
55.6
0.0
192605
55.3
-0.3
192705
55.8
0.2
192805
55.5
-0.1
192905
55.4
-0.2
193005
55.1
-0.5
193105
55.4
-0.2
193205
56.8
1.2
193305
57.1
1.5
193405
57.4
1.8
193505
56.8
1.2
193605
56.1
0.5
193705
56.1
0.5
193805
55.8
0.2
193905
56.7
1.1