Illinois, Climate Division 1 36-Month Period Ending in May Average Temperature
Degrees Fahrenheit
1901-2000
-99
189805
48.4
0.2
189905
47.4
-0.8
190005
47.8
-0.4
190105
47.6
-0.6
190205
48.3
0.1
190305
48.1
-0.1
190405
46.8
-1.4
190505
46.1
-2.1
190605
46.2
-2.0
190705
47.3
-0.9
190805
47.9
-0.3
190905
47.9
-0.3
191005
47.8
-0.4
191105
48.1
-0.1
191205
47.3
-0.9
191305
47.4
-0.8
191405
47.7
-0.5
191505
48.6
0.4
191605
48.2
0.0
191705
47.2
-1.0
191805
46.1
-2.1
191905
47.0
-1.2
192005
47.2
-1.0
192105
49.1
0.9
192205
49.4
1.2
192305
49.8
1.6
192405
48.7
0.5
192505
47.8
-0.4
192605
47.4
-0.8
192705
47.3
-0.9
192805
47.6
-0.6
192905
47.6
-0.6
193005
47.7
-0.5
193105
48.1
-0.1
193205
49.7
1.5
193305
50.0
1.8
193405
50.1
1.9
193505
49.3
1.1
193605
48.5
0.3
193705
48.2
0.0
193805
48.2
0.0
193905
49.4
1.2
194005
49.1
0.9
194105
49.1
0.9
194205
49.2
1.0
194305
48.9
0.7
194405
48.6
0.4
194505
48.1
-0.1
194605
48.5
0.3
194705
48.3
0.1
194805
48.2
0.0
194905
48.4
0.2
195005
48.7
0.5
195105
47.8
-0.4
195205
47.1
-1.1
195305
47.3
-0.9
195405
48.7
0.5
195505
49.6
1.4
195605
49.4
1.2
195705
49.0
0.8
195805
48.3
0.1
195905
47.9
-0.3
196005
47.3
-0.9
196105
47.4
-0.8
196205
47.6
-0.6
196305
47.4
-0.8
196405
47.9
-0.3
196505
48.0
-0.2
196605
48.3
0.1
196705
47.8
-0.4
196805
47.7
-0.5
196905
47.8
-0.4
197005
47.4
-0.8
197105
47.5
-0.7
197205
47.8
-0.4
197305
48.3
0.1
197405
48.8
0.6
197505
48.3
0.1
197605
48.9
0.7
197705
48.0
-0.2
197805
47.4
-0.8
197905
46.1
-2.1
198005
46.5
-1.7
198105
47.7
-0.5
198205
48.1
-0.1
198305
48.4
0.2
198405
48.0
-0.2
198505
48.8
0.6
198605
48.3
0.1
198705
49.1
0.9
198805
49.1
0.9
198905
49.7
1.5
199005
49.0
0.8
199105
49.3
1.1
199205
49.6
1.4
199305
49.0
0.8
199405
48.0
-0.2
199505
47.7
-0.5
199605
47.9
-0.3
199705
47.8
-0.4
199805
48.3
0.1
199905
49.6
1.4
200005
51.0
2.8
200105
50.1
1.9
200205
50.0
1.8
200305
49.3
1.1
200405
50.0
1.8
200505
49.6
1.4
200605
50.4
2.2
200705
50.3
2.1
200805
50.0
1.8
200905
48.8
0.6
201005
48.5
0.3
201105
48.6
0.4
201205
50.3
2.1