The wild temperature swings felt in Illinois this January canceled each other out, averaging to 26.7 degrees, just a fraction of a degree above average. Climatologist Jim Angel calls the temperature swings impressive, but also typical of winter in Illinois. He says the first nine days of January were above average, followed by four days below average, then three days above average. The second half of the month started much below average, but steadily warmed. The temperature was 20 degrees above average by the end of the month. January snowfall ranged from 2 to 5 inches in most places. Western Illinois saw 5 to 7.5 inches, but most of Illinois received below-average snowfall.