CHAMPAIGN — A warmer than normal summer season continued in July with temperatures nearly 2 degrees above average, according to Illinois State Climatologist Trent Ford at the University of Illinois’ Illinois State Water Survey. Precipitation was also above normal in July.
The preliminary statewide average July temperature was 77.2 degrees, 1.8 degrees above the 30-year normal. Preliminary statewide average total precipitation for July was 5.79 inches, 1.71 inches wetter than normal.
Elevated temperatures and abundant humidity were caused by persistent atmospheric flow from the Gulf of Mexico and actively transpiring crops. Overall, July temperatures ranged from the mid-70s in northern Illinois to the mid-80s in southern Illinois, between 1 and 5 degrees above average.
The hot and humid conditions led to a very active month for severe weather. The NOAA Storm Prediction Center reported 10 tornado, 22 hail, and 154 wind reports in Illinois during July. Although areas of the state needed the rain that accompanied severe thunderstorms, several producers reported widespread crop damage from hail and strong winds.
July was wetter than normal for most of the state, and areas of central and southeast Illinois received 4 to 6 inches more than the average July rainfall. Heavy rain in these regions alleviated the acute dry conditions that continued from June and the first half of July.
July total precipitation ranged from over 13 inches in central and eastern Illinois to less than 2 inches in the northeast. Single-day precipitation total records were broken at 88 stations across the state. Five of those stations broke the July all-time daily precipitation records.
The Peoria airport station recorded 5.15 inches in just six hours on July 15, marking the highest six-hour rainfall total on record in Peoria. Twenty-four-hour rainfall totals from this event exceeded 6 inches in parts of Tazewell and Woodford counties, resulting in widespread flash flooding in agricultural and residential areas.
Last month was also the wettest July on record at Casey in Clark County, Minonk in Woodford County, and Clay City in Clay County.
Although the heat is moderate at the beginning of August, short-term 8- to 14-day outlooks from the NOAA Climate Prediction Center suggest elevated odds of above normal temperatures in the second week of August. The state also has slightly elevated odds of wetter than normal conditions over the same time period.
Despite the short-term outlook, one-month outlooks indicate elevated odds of below normal temperatures for the month of August, with the strongest odds of near-normal precipitation.