October 2021 in Illinois was the eighth warmest and the fourth wettest October on record going back to 1895, according to Illinois State Climatologist Trent Ford at the University of Illinois’ Illinois State Water Survey.

Following a warm start to fall in September, temperatures were consistently 5 to 10 degrees above normal for the first half of October. The statewide average October temperature was 59.7 degrees, 5.1 degrees above the 1991–2020 average. These numbers are preliminary, and official numbers and rankings will be released later.

October average daily minimum temperatures r...