August 15-21, 2025

Temperatures

Average temperatures were above normal regionwide, save Michigan’s UP (Figure 1). West of the Mississippi River, temperatures averaged as much as 6-8°F above normal for the week. East of the Mississippi River, temperatures averaged 3-6°F above normal for the week.

Minimum temperatures averaged even more above normal. Minimum temperatures were nearly 10°F above normal in parts of western Iowa and western Minnesota (Figure 2). East of the Mississippi River, minimum temperatures were 3-6°F above normal.

Maximum temperatures were slightly below normal by 1-3°F across Michigan’s UP, Minnesota’s Arrowhead region, and northern Wisconsin (Figure 3). They were near normal through the rest of Michigan and Wisconsin. The rest of the region saw above normal maximum temperatures, ranging from 2-4°F above normal in the Ohio Valley to nearly 10°F above normal across southern Missouri. In Springfield, Missouri, temperatures remained at or above 97°F for five consecutive days, which was the longest stretch of such heat in August since 2014.

Precipitation

Southern Minnesota was the rainfall winner with over 400 percent of normal precipitation (Figure 4). Southern Wisconsin, Chicagoland, Northwest Indiana, and Michigan’s UP all observed over 200 percent of normal precipitation. Precipitation was sparse outside the aforementioned locations, with little to no precipitation observed for the week across Kentucky, Missouri, and southern Ohio.

A heavy rainfall event at the beginning of the week brought several inches of rain to southern Minnesota. In Lamberton, Minnesota, 3.46 inches of precipitation fell during the 24-hour period ending on August 17, which was he second wettest August day on record since 1961. The Twin Cities observed two consecutive days of precipitation greater than one inch from August 16-17 for the first time in August since 2016 and only the seventh time in August since 1871.

With drier conditions across the southern reaches of the region, D1 (moderate drought) expanded across the Missouri Bootheel and Central Kentucky. This was the opposite of the Upper Midwest, where slight improvements in D1 were made across Mid-Michigan (Figure 5).

Severe Weather

A 79-mph wind gust was reported at a mesonet station in Yellow Medicine County, Minnesota, on August 15. An EF-U tornado briefly touched down in a field in Champaign County, Illinois, on August 16, while 3-3.5-inch diameter hail was reported in Stephenson County, Illinois, on the same day. A person was injured in Monroe County, Indiana, when a tree fell on their tent at a campsite on August 16.