September 15-21, 2025

Temperature

Average temperatures were above normal. In parts of the Upper Midwest, they averaged over 10°F above normal (Figure 1). Elsewhere, they were generally 5-10°F above normal, with slightly lower anomalies over eastern Kentucky.

Minimum temperatures were similarly anomalous, averaging nearly 15°F above normal for the week across portions of Minnesota and Wisconsin (Figure 2). While the northwest was significantly above normal, the eastern parts of the region were less anomalous. Minimum temperatures were just 2-4°F above normal across the Ohio Valley, with near normal minimum temperatures over Greater Cleveland and eastern Kentucky. One station in Pine River Dam, Minnesota, with records dating back to 1887, observed a minimum temperature of 69°F, which has only happened 3 times before after September 15 in the calendar year.

Maximum temperatures were most anomalous over the middle of the region. Maximum temperatures were 10°F above normal along I-70 from Ohio all the way to Missouri (Figure 3). Maximum temperatures were still above normal over the Upper Midwest by 5-10°F. In Carrollton, Missouri, a station with records dating back to 1893 observed seven consecutive days of maximum temperatures above 90°F, September 12-18. This was the longest stretch of 90&degF+ temperatures in Carrollton in September since 1990 and tied for the third longest in September on record. St. Louis observed its longest stretch of 90°F+ temperatures since 2015.

Precipitation & Drought

Conditions were driest over much of Kentucky, Ohio, and eastern Indiana, where precipitation was less than 25 percent of normal, at best (Figure 4). The wettest conditions were observed west of the Mississippi River, particularly western Iowa and western Minnesota, where some spots were over 200 percent of normal.

Drought continued to expand, especially across the south and east. For the first time since November 2024, D3 (extreme drought) was reintroduced to the region, specifically in the Missouri Bootheel and eastern Ohio (Figure 5). In Illinois, Indiana, Kentucky, Missouri, and Ohio, there is D1 (moderate drought) in at least half of each respective state. D2 (severe drought) also expanded across southern Illinois, southern Missouri, and western Kentucky. At least one-third of the Midwest is now experiencing drought conditions.

Severe Weather

Storms over Iowa on September 16 produced quarter-sized to half-dollar-sized hail. On September 18, a storm produced 70-80 mph wind gusts over western Missouri. On September 21, hail the size of hen eggs was reported in Hennepin County, Minnesota.