What is Chicago’s greatest temperature rise during one calendar day, from early morning to late afternoon?
Chicago climatologist Frank Wachowski combed the record books and found that Chicago’s biggest one-day warm-up was 49 degrees logged on March 29, 1895. The day’s low of 31 degrees occurred just after midnight as increasing southwest winds sent temperatures climbing. By 7am the mercury had risen to 42 degrees and by late afternoon, under bright sunshine and southwest winds gusting as high as 41 mph, temperatures peaked at an unseasonably warm 80 degrees. The 49-degree span between the daily high and low was the city’s third largest on record. The two larger ones were declines, 52 degrees from 62 to 10 on February 8, 1900 and 51 degrees from 42 to minus 9 on January 13, 1888.