Below are the average monthly temperatures in degrees Farenheit for Chicago, Illinois as recorded by the National Weather Service between 1971 and 2000. These temperatures were taken at O'Hare International Airport.
January
- High - 29.6
- Low - 14.3
- High - 34.7
- Low - 19.2
- High - 46.1
- Low - 28.5
- High - 58.0
- Low - 37.6
- High - 69.9
- Low - 47.5
- High - 79.2
- Low - 57.2
- High - 83.5
- Low - 63.2
- High - 81.2
- Low - 62.2
- High - 73.9
- Low - 53.7
- High - 62.1
- Low - 42.1
- High - 47.1
- Low - 31.6
- High - 34.4
- Low - 20.4
