July 2024 Overview – Midwestern Regional Climate Center

Temperature

The average July temperature for the Midwest was 72.4°F, which was 0.3°F below the 1991-2020 normal (Figure 1). This breaks an 11 consecutive month stretch of above-normal monthly temperatures for the Midwest region. Temperatures were 1-3°F below normal in the central Midwest, with slightly above-normal temperatures in the far northwest and far southeast portions of the region (Figure 2). Statewide average temperatures ranged from 1.4°F below normal in Missouri to 0.9°F above normal in Minnesota (Figure 1). Near-average to cooler-than-average daytime highs were notable across the region in July (Figure 3). Only one station across the region, in southwest Missouri on July 3, reached a triple-digit temperature during the entire month. On July 19th, Decatur, Illinois recorded a minimum temperature of 49°F. This was just the third time in the last 40 years that this station dipped below 50°F in the month of July.

Precipitation

July precipitation totaled 4.61 inches for the Midwest, which was 0.51 inches above normal, or 112 percent of normal (Figure 1). Precipitation was 1-6 inches above normal in the central Midwest, with deficits of 1-3 inches in the far northern and far eastern portions of the region (Figure 4). Statewide precipitation totals ranged from 2.3 inches above normal in Illinois to 1.22 inches below normal in Ohio (Figure 1). Final rankings indicate that Illinois had the 7th wettest July on record. Numerous long-running stations had a top five wettest July including Jackson (MI), Cedar Rapids (IA), Flint (MI), Winnebago (MN), and Sioux City (IA) (Figure 5). Columbia, Missouri had its 3rd wettest July since 1889 with 11.23 inches of rain, of which 10.15 inches fell during the seven-day period from July 3-9, 2024 (2nd highest 7-day total on record). July rainfall around a wide swath of the St. Louis area, including portions of western Illinois, totaled 12-16 inches from the CoCoRaHS network (Figure 6). Repeated storms and rainmaking events plagued the Midwest, with measurable precipitation recorded on 11-16 days across much of the region (Figure 7). Two notable events are further detailed below. However, much of Ohio missed out on the soaking rains during July. Mansfield, in north-central Ohio, had its 3rd driest July in 105 years with just 1.24 inches of rain. Drought conditions expanded in Ohio with 40 percent of the state ending the month in drought and 32 percent abnormally dry (Figure 8).

Remnants of Hurricane Beryl

On July 9-10, the remnants of Hurricane Beryl traversed the Midwest, dumping 2-9 inches of rain along a line from southern Missouri to eastern Michigan (Figure 9). The storm also blanketed the region with 35-45 mph wind gusts, minor to moderate river flooding, and a few tornadoes.

July 15-16 Derecho

A widespread, long-lived windstorm (derecho) moved across Iowa, Illinois, Indiana, and southern Michigan on July 15-16 (Figure 10). This storm system was accompanied by heavy rainfall, 60-100 mph wind gusts, and numerous tornadoes that resulted in widespread power outages, downed trees, and damaged structures. At least 54 tornadoes were confirmed by National Weather Service offices across the region. The Chicagoland area had its largest single-day tornado outbreak on record with 32 confirmed tornadoes on July 15.