December was the warmest and second-wettest for that month on record in Illinois, according to Illinois State Climatologist Jim Angel, of the Illinois State Water Survey.
The statewide average temperature for December was 40.6 F, 10.7 degrees above average, making it the warmest December on record. The month beat the old record – set in 1923 with 38.9 degrees – by 1.7 degrees.
The statewide average precipitation was 6.7 inches, 4.01 inches above average and the second-wettest on record. The wettest December on record was in 1982 with 7.17 inches. Like this year, that also was during a major El Niño event.
The record-setting December finishes off the sixth-wettest year on record with 48.49 inches, 8.53 inches above average. The warmer December was offset by a very cold February. As a result, the annual average temperature for Illinois was 52.8 degrees, 0.4 degrees above average.
Source: Jim Angel, 217- 333-0729, jimangel@illinois.edu