September 1-7, 2021
Slighter Cooler Temperatures
Average temperatures across the region were near normal to cooler than normal to kickoff the month, with the exception of extreme southwestern Missouri (Figure 1). Maximum temperatures were 2-4°F cooler than normal for most areas (Figure 2). Minimum temperatures were 2-3°F above normal along the far western edge of the region, but the majority of the Midwest saw near normal to below normal minimum temperatures (Figure 3).
Mixed Amounts of Precipitation
Precipitation was measured across most of the Midwest, although amounts varied widely (Figure 4). The greatest rainfall was measured in the southern Midwest, with 1-3 inches falling across Missouri and the Ohio River Valley. Western Minnesota and northern Iowa also saw above normal precipitation. Little precipitation in the Great Lakes region resulted in most areas with less than 50 percent of normal rainfall for the week (Figure 5).
Drought Continues in Northwest Portion of the Region
Drought conditions lingered this week, affecting about one-quarter of the Midwest and mostly contained in the northwestern portion of the region (Figure 6). Minnesota had the most extensive drought conditions covering about 86 percent of the state, including nearly six percent of the state remaining in D4 Exceptional Drought on the U.S. Drought Monitor. However, cooler temperatures and increased precipitation allowed many Minnesota counties to begin reducing or removing burn restrictions that had been implemented in August.
Strong Storms on September 7
A large low pressure system moved across the upper Midwest on September 7, triggering widespread damaging weather that resulted in 224 storm reports across Wisconsin, Illinois, and Michigan (Figure 7). There were numerous reports of large hail in the Appleton, Wisconsin area, including several reports of hail exceeding 4 inches. A National Weather Service storm damage survey concluded wind speeds topped 85 mph in Minooka, Illinois and Channahon, Illinois. There numerous reports of downed power lines and large trees as well as collapsed out buildings and damaged homes.