Cooler Temperatures Return

Cooler temperatures settled into the Midwest this week (Figure 1) with every state running below normal except Kentucky (0.6°F above normal) and Missouri (0.4°F above normal). Preliminary temperature data showed that the coolest temperatures occurred in Michigan (2.4°F below normal) and Wisconsin (2.6°F below normal). Sheboygan County, Wisconsin observed a 61.7°F average temperature for the week. The station’s lowest minimum temperature was 49°F, which occurred on August 12. Maximum temperatures were well below normal for most of the Midwest (Figure 2). Areas in northern Wisconsin experienced maximum temperatures greater than 4°F below normal. Southern and western Iowa, and western Missouri, experienced temperatures less than 3°F above normal. Minimum temperatures were also below normal for the upper Midwest (Figure 3). Northern Michigan had locations that were up to 6°F below normal. There were 2 maximum and 64 minimum daily high temperature records broken or tied. Additionally, there were 9 minimum and 70 maximum daily low temperature records broken or tied this week.

Isolated, Heavy Rainfalls Continue

Precipitation continued to be isolated and a few locations received over 2 inches this week (Figure 4). Northwestern Illinois (Climate Division 1), northeastern Wisconsin (Climate Division 6), western Michigan (Climate Division 5), and northwestern Ohio (Climate Division 1) all averaged greater than 200 percent of normal precipitation (Figure 5). Oceana County, Michigan received 3.65 inches of rain, which was 2.9 inches above normal. The location received 2.43 inches of rain on August 14. The driest locations in the Midwest were west-central Illinois and southeast Illinois (less than 50 percent of normal), northern Missouri (less than 25 percent of normal), and western and central Iowa (less than 50 percent of normal). Preliminary state average precipitation for Iowa was 0.49 inches, which was exactly 50 percent of normal for the week. Southwest Iowa (Climate Division 7) received 8 percent of normal rainfall. The lack of precipitation in these locations can be seen in the 7-day average streamflows (Figure 6). Above normal streamflows continued through most of eastern Kentucky.

Drought Monitor Update

The August 9, 2022 US Drought monitor showed a 5% improvement to the Midwestern area considered in the Moderate Drought (D1), Severe Drought (D2), and Extreme Drought (D3) categories compared to the previous week (Figure 7). The Midwest also had reductions in the area considered in Abnormally Dry (D0) conditions this week. The largest changes occurred in southern Iowa, southwestern Missouri, and west-central Indiana. The D2 drought in southern Iowa was downgraded to a D1 and the D3 in southwestern Missouri was largely reduced to a D2. The D1 in west-central Indiana was reduced in size.

Storm Reports

Storm reports were relatively quiet in the Midwest this week, with four hail reports and 34 wind reports. Hail reports occurred on August 8 and 11, where all were less than 1.50 inches in diameter. On August 8, 28 wind reports occurred in Missouri and Ohio. The highest measured wind speed was 64-mph in Greene County, Missouri. There were several reports of large trees downed, utility poles blown over, and minor building damage.