July Rainfall in Illinois Varied from Too Dry to Too Wet

The statewide average rainfall for July in Illinois was 4.12 inches, only 0.29 inches above average. However, rainfall across the state varied widely from too dry to too wet.

Rainfall amounts in the northern third of the state were impressive with widespread areas in excess of 6 to 8 inches. The heaviest rains fell around Galena. A CocoRaHS observer (IL-JD-2) reported a monthly rainfall total of 19.21 inches while the nearby Galena NWS Coop observer reported 17.78 inches. In nearby towns:

  • Elizabeth reported 16.74 inches (NWS),
  • Freeport reported 12.08 inches (CoCoRaHS), and
  • Mt. Carroll reported 11.33 inches (NWS).
Chicago O’Hare airport had a July rainfall total of 11.15 inches, their wettest July on record, thanks largely to the 6.86 inches that fell in three hours on July 23.

The middle third of Illinois was exceptionally dry. Some of the smaller rainfall totals for July were just south and west of the heavy rainfall in northwest Illinois. One of the drier sites was Aledo with only 0.55 inches. Amounts of only 1 to 2 inches were common in central Illinois. This equates to rainfall departures that were generally 50-75 percent of average (or worse) across the region. Champaign-Urbana experienced its 20th driest July on record with only 1.58 inches, 3.12 inches below average. Springfield reported 1.09 inches and Peoria reported 1.66 inches.

The southern third of Illinois was wet, where amounts of 4 to 8 inches or more were common. The largest July rainfall total was at the NWS Du Quoin site with 8.88 inches.

July 2011 rainfall in Illinois
July 2011 rainfall in Illinois. Click to enlarge.
July 2011 rainfall departure for Illinois
July 2011 rainfall departure from average for Illinois. Click to enlarge.
Advertisements

One thought on “July Rainfall in Illinois Varied from Too Dry to Too Wet

Comments are closed.