Fourth Warmest October

Temperatures across the Midwest were unseasonably warm for October (Figure 1). The region averaged 57.1°F, which was 5.7°F above normal. This ranked as the fourth warmest October on record dating back to 1895. All states were warmer-than-normal, with temperature departures ranging from 3.9°F above normal in Missouri to 7.1°F above normal in Michigan. Ohio had the warmest October on record dating back 127 years. Illinois (5th, tied), Indiana (5th), Michigan (3rd), Minnesota (5th), and Wisconsin (4th) all had a top five warmest October (records from 1895-2021). Minimum temperatures were a major driving factor for the October warmth. Monthly minimum temperatures ranged from 3-11°F above normal (Figure 2), and 808 maximum low temperature records were recorded during October. Nearly all the maximum low temperature records occurred during the first 15 days of the month. Warm minimum temperatures also resulted in the first fall freeze across the upper Midwest being delayed by two to four weeks compared to the 1981-2010 median freeze date. By the end of October, few locations across the lower Midwest had reached the first fall freeze (Figure 3). Monthly maximum temperatures were 1-7°F above normal (Figure 4), and 133 maximum high temperature records were recorded during October.

Seventh Wettest October

Precipitation was wetter-than-normal during October (Figure 5). Average precipitation was 4.40 inches, which was 1.3 inches above normal. This ranked as the 7th wettest October on record dating back to 1895. Precipitation amounts across the Midwest varied from 3-10 inches, except for a dry area centered around central Wisconsin where monthly precipitation ranged from 1-3 inches (Figure 6). All states had above-normal precipitation except Wisconsin, which was 1.00 inches below normal. Illinois (4th), Indiana (6th), Iowa (6th), and Missouri (9th) all had precipitation totals within the top nine wettest on record dating back 127 years. There were 697 high precipitation records in October. Illinois (156) and Iowa (153) had the greatest number of precipitation records.

Drought Improves, Except in Wisconsin

Drought conditions affected about 19 percent of the Midwest by late October, with about 17 percent of the region flagged as abnormally dry according to the U.S. Drought Monitor (Figure 7). Although drought persisted, conditions did improve throughout the month in Minnesota, Iowa, and Illinois (Figure 8). Wisconsin and the Upper Peninsula of Michigan saw the greatest expansion and intensification of drought in the Midwest. About 94 percent of Wisconsin was abnormally dry or in drought compared to 38 percent 3 months ago.

Crop Harvest Slows

Wetter-than-normal conditions caused corn harvest to slow in the eastern portion of the region. Kentucky, Indiana, and Ohio were 3-8 percent behind the 5-year average (Figure 9). Northern areas, which had a head-start on corn harvest last month, continued to track 10-22 percent ahead of the 5-year average. Soybean harvest was slowed significantly across the Midwest in October, with only three states (Iowa, Minnesota, and Wisconsin) ahead of the 5-year average (Figure 10). Soybean harvest in Illinois, Indiana, and Michigan was 11-15 percent behind the 5-year average. Sugarbeet harvest, which is negatively impacted by warm temperatures, was 15 percent behind the 5-year average in Minnesota. Delays in the first fall freeze resulted in continued insect pressure in the region. An Extension specialist in Ohio reported ongoing army worm damage through late October, which was extremely rare.

Active Month for Severe Weather Severe weather was reported on 14 out of 31 days in October across the Midwest. This included 71 tornadoes reports, 116 severe wind reports, and 6 hail reports. There was one injury associated with a tornado in Ohio on October 15. Two EF-3 tornadoes in Missouri on October 24 each resulted in one injury. October 24 was the most active severe weather day of the month, with 22 tornadoes and 39 wind events reports across Missouri, Illinois, and Indiana.