Illinois, Climate Division 3 18-Month Period Ending in May Average Temperature
Degrees Fahrenheit
189705
47.4
189805
47.6
189905
45.4
190005
46.0
190105
46.9
190205
46.6
190305
46.3
190405
44.8
190505
44.1
190605
46.1
190705
46.8
190805
47.0
190905
47.7
191005
47.0
191105
46.9
191205
46.3
191305
45.7
191405
48.3
191505
48.1
191605
46.0
191705
45.9
191805
44.2
191905
46.9
192005
47.2
192105
47.9
192205
49.9
192305
47.9
192405
46.5
192505
46.6
192605
46.6
192705
46.6
192805
47.5
192905
46.6
193005
46.5
193105
48.5
193205
50.2
193305
48.4
193405
48.9
193505
48.9
193605
45.7
193705
46.8
193805
47.7
193905
49.4
194005
47.3
194105
47.2
194205
49.2
194305
47.4
194405
46.6
194505
47.5
194605
47.1
194705
47.5
194805
47.2
194905
47.6
195005
47.7
195105
45.8
195205
45.8
195305
47.9
195405
49.2
195505
49.2
195605
47.8
195705
47.8
195805
46.9
195905
46.3
196005
46.0
196105
46.3
196205
46.2
196305
46.0
196405
47.2
196505
46.8
196605
46.5
196705
46.9
196805
46.1
196905
46.5
197005
45.8
197105
46.1
197205
47.3
197305
46.8
197405
48.0
197505
46.6
197605
48.0
197705
46.8
197805
45.0
197905
43.7
198005
45.1
198105
47.7
198205
46.5
198305
46.2
198405
47.5
198505
46.5
198605
47.0
198705
48.5
198805
49.1
198905
47.7
199005
47.3
199105
48.6
199205
49.1
199305
47.0
199405
45.9
199505
47.2
199605
46.4
199705
45.4
199805
47.8
199905
50.0
200005
49.7
200105
47.9
200205
47.9
200305
48.1
200405
47.8
200505
48.5
200605
49.8
200705
49.0
200805
48.1
200905
46.3
201005
46.6
201105
47.5
201205
49.6
201305
49.7
201405
45.5
201505
44.8
201605
48.9
201705
51.0
201805
48.8
201905
47.2