Wet in the Southeast and Parts of Minnesota
A large part of the Midwest, including most of Missouri, Illinois, Iowa, Wisconsin, and Michigan received just 25% to 75% of normal precipitation in September. Amounts in Ohio, Indiana, and Kentucky were generally between 75% and 125% of normal with a few areas topping 125%
(Figure 1). The wettest area in the region was west central Minnesota where totals topped 200% of normal. Stations in Minnesota ranged from a couple inches above normal to an inch or more below normal at stations that were only a county or two away. Drought conditions degraded slightly in September with a small areal expansion (Figure 2). The area affected was roughly from southern Minnesota to northern Missouri and eastward to include northern and central Illinois, and southwest Wisconsin.
Warm Temperatures in the West
Warmth in the western half of the Midwest gave way to more seasonable temperatures in the eastern half of the region. Monthly averages were 2°F to 4°F above normal across most of Minnesota, Iowa, and Missouri
(Figure 3). Early in the month, days in the mid to upper 90s were recorded across much of the Midwest and triple digit readings even came in from Iowa, Illinois, Indiana, and Missouri. The first freezes of the fall season occurred in the northern sections of the region in September (Figure 4).
Warm conditions helped corn and soybean crops reach maturity in the western two thirds of the region while in the east the crops were already close to normal. By the end of the month, the percentage of the crop at maturity was closer to normal though still behind slightly except for soybeans in Ohio and Indiana. Harvest was also running behind the 5-year average in all cases except soybeans in Ohio.