Above Normal Temperatures

September temperatures averaged 65.9°F in the Midwest, which was 2.3°F above normal (Figure 1). Michigan, Ohio, and Wisconsin were 1.5-1.9°F above normal. Illinois, Indiana, Iowa, Minnesota, and Missouri were 2.4-3.2°F above normal. Kentucky was very near normal for September, with average temperature 0.1°F above normal. There were 251 maximum high temperature records across the Midwest, with most occurring on September 14th through 21st and September 27th through 30th. Minnesota (62), Iowa (41), and Illinois (40) experienced the most record maximum high temperatures. There were 138 maximum low temperature records during the month, with double digit records broken on September 12th, 20th, and 30th. Minnesota (40), Illinois (23), and Ohio (21) saw the most maximum low temperature records.

Below Normal Precipitation

Regionwide precipitation was 2.84 inches, which was 0.58 inches below normal (Figure 2). Precipitation totals varied from 0.5 inches to 8 inches across the Midwest (Figure 3). The most abundant precipitation fell in the east over a region extending from central Kentucky northeastward into southeast Michigan. Precipitation within this area ranged from 150 to 200 percent of normal (Figure 4). A broad corridor extending from northern Missouri to the northeast up through Iowa, Illinois, and Wisconsin had the lowest rainfall in the region, with percent of normal precipitation between 25 to 50 percent. There were 236 high precipitation records in September with about half of those records being set from September 21st to 23rd. Ohio (48) and Indiana (39) had the greatest number of precipitation records, occurring in the same period.

Drought Lingers

About 23 percent of the Midwest remained in D1-D3 drought by late September, and 19 percent of the region was abnormally dry (D0) (Figure 5). Drought conditions improved throughout Minnesota compared to last month. In Minnesota, near normal statewide precipitation helped to eliminate all D4 (exceptional drought) from the northern reach of the state, and D3 (extreme drought) coverage declined 13 percent. However, D2 (severe drought) remained across 50 percent of Minnesota to end the month. Drought conditions worsened in Iowa, northern Illinois, and southern Wisconsin (Figure 6). Abnormal dryness expanded in Missouri and contracted in Indiana.

Severe Weather

Severe weather was reported on 11 out of 30 days in September across the Midwest. While all nine states were impacted, the number of severe weather reports varied significantly across the region. Indiana, Kentucky, and Ohio each had fewer than 10 reports statewide (for all hazards) whereas Michigan and Wisconsin each recorded over 100 events. Five days recorded double digit events across the region, with one day (September 7th) recording 224 events. Hail (119) and wind (104) were the top severe weather issues on September 7th, with one tornado reported (in Illinois). A total of seven tornadoes were reported regionwide during September. Unfortunately, severe weather (wind) was responsible for one fatality and one injury in Missouri on September 14. Severe wind also resulted in one fatality in Minnesota on September 16.

Crop Maturity Ahead of Schedule

Favorable weather during September lead to corn and soybeans maturing rapidly across the region, which resulted in ahead-of-schedule harvest for the majority of the Midwest. All states except Kentucky were 5 to 13 percent ahead of the 5-year average for corn harvest. Kentucky was 16 percent behind average after several weeks of above average rainfall created less favorable corn harvest conditions. All states were at or ahead of the 5-year average for soybean harvest. States in the southern Midwest were zero to seven percent ahead whereas northern states were 16 to 31 percent ahead.