North to South Temperature Divide

Temperatures were split across the region to start the month of August. Average temperatures were 1-4.8°F below normal across the lower Midwest and 1-6°F above normal across the far upper Midwest, with near normal conditions in between (Figure 1). Hart County, Kentucky, recorded an average temperature of 70.7°F, which was 4.8°F below normal for the week. Koochiching County, located in northern Minnesota, observed an average temperature of 70.9°F (6°F above normal). Maximum (Figure 2) and minimum (Figure 3) temperatures followed a similar pattern.

Isolated Wetness

Ample precipitation fell in Wisconsin, western Michigan, southern Illinois, and extreme southern Missouri this week, with those locations recording over 200 percent of normal precipitation (Figure 4). La Crosse County, Wisconsin, received 8.04 inches of precipitation (6.74 inches above normal). However, most of the Midwest had less than one inch of precipitation (Figure 5), equating to less than 50 percent of normal precipitation. Portions of northern Minnesota received 2-25 percent of normal precipitation. Central Indiana also recorded 5-25 percent of normal precipitation.

Minnesota Drought Record

As of August 10, 25 percent of the Midwest was in drought, with 95 percent of Minnesota in drought and 52 percent of Iowa in drought (Figure 6). For the first time in the US Drought Monitor’s history (since 2000), Minnesota had areas in the D4-Exceptional Drought category, which is the worst category of drought. A persistent pattern of above normal temperatures and below normal precipitation across Minnesota resulted in rapidly worsening drought conditions over the past 8 weeks (Figure 7).

Severe Weather

Severe weather was reported on 7 out of 10 days during this period, including a total of 25 tornado reports, 49 hail reports, and 216 wind reports. August 9 was the most active day for tornadoes, most occurring in northern Illinois (Figure 8), while August 10 was the most active for severe wind (Figure 9). All of the tornadoes were EF-1 or EF-0. There were 10 reports with winds exceeding 65 mph across Iowa, Wisconsin, Illinois, and Michigan. In Montcalm, Michigan, there was major damage to a grain elevator reported. No injuries or fatalities were reported. Combined with the severe weather, Ionia, Iowa, reported 11 inches of rain in 24 hours.