The average June temperature for the Midwest was 69.4°F, which was 0.4°F above the 1991-2020 normal. Temperatures were up to 5°F above normal in the northwest and up to 4°F below normal in the southeast (Figure 1). Maximum (Figure 2) and minimum temperatures (Figure 3) followed a similar west-to-east pattern. Statewide average temperatures ranged from 4.2°F above normal in Minnesota to 2.8°F below normal in Kentucky and Ohio (Figure 4). Rankings indicate Minnesota tied for the 4th warmest June since 1895. Minneapolis-St. Paul had the 3rd warmest June in 151 years. Over 500 daily high temperature records were broken or tied in June, with nearly all of those occurring from June 1-5 (Figure 5). Over 380 daily low temperature records were broken or tied in June, with a large portion of those records occurring from June 8-16 (Figure 6). Dangerous heat index values settled across the lower Midwest in late June. Heat index values ranged from 100-115°F across Missouri, southern Illinois, southern Indiana, and western Kentucky on multiple days during the last week of June.
June precipitation totaled 2.42 inches for the Midwest, which was 2.12 inches below normal, or 53 percent of normal (Figure 4). Based on final rankings, the Midwest had the 5th driest June since 1895. All nine Midwestern states measured below-normal precipitation, with totals ranging from 0.75 inches below normal in Kentucky to 2.84 inches below normal in Illinois. Rankings indicate Wisconsin was 5th driest June on record, while Missouri was 6th driest. Illinois had the 8th driest June since 1895. A large portion of the Midwest had less than 50 percent of normal precipitation in June, with patchy areas of 10-25 percent of normal precipitation (Figure 7). Charles City, Iowa, had its driest June in 131 years, with just 0.37 inches of precipitation for the month. Hasting, Michigan, had its driest June in 120 years of observations. Minneapolis-St. Paul had the 2nd driest June in 151 years. Muskegon, Michigan, had the 3rd driest June in 124 years. Notably, numerous locations in Illinois, Indiana, Michigan, Ohio, and Wisconsin exceeded 20 consecutive days without precipitation from May into early June. Knoxville and Galesburg, Illinois, went 27 days without rainfall from May 15 to June 10. Conversely, central Kentucky had near- to above-normal precipitation in June, with a wide swath of the region accumulating up to 7.5 inches for the month (Figure 8). Numerous central Kentucky stations reported one-day rainfall totals of 2-4 inches on June 26 (Figure 9).
A lack of rainfall, low humidity, and abundant sunshine resulted in drought expansion and intensification across the Midwest in June. By month’s end, about 65 percent of the region was in drought, and 26 percent was abnormally dry, according to the U.S. Drought Monitor (Figure 10). Drought affected all nine Midwest states. Extreme (D3) drought conditions were reported in central and northeast Missouri and southeast Iowa. A large portion of Illinois and Indiana were degraded to severe drought (D2). The only locations with drought improvement in June were Kentucky and central Ohio. Elevated fire danger was widespread across Michigan for the first several weeks of June. In early June, a wildfire burned 3,600 acres in northern Michigan, prompting evacuations and closing a 5-mile stretch of Interstate 75. With just 3 days, the Indianapolis Airport had the fewest number of June days on record where the dew point temperature reached or exceeded 65°F. By late June, topsoil moisture was short to very short on over 85 percent of cropland in Illinois, Michigan, and Missouri (Figure 11). In those same states, corn conditions were rated poor to very poor on 25-30 percent of acres (Figure 12).
Ongoing Canadian wildfires and a persistent upper air pattern resulted in an excessive number of air quality alerts across the Midwest in June. Most NWS offices across the region issued over 20 alerts during the month. The NWS in Northern Indiana issued 46 alerts, the highest in the country. The Air Quality Index (AQI) exceeded 101 (unhealthy for sensitive groups) nearly every day of the month, with about half the days exceeding 151 (unhealthy). The worst air quality was measured on June 27 and June 28 when the AQI exceeded 201 (very unhealthy) across a large portion of the central Midwest, including areas near Madison, Chicago, Indianapolis, Detroit, and Cleveland.
June 25 Severe Weather Outbreak
A frontal system traversed the Midwest on June 25, prompting high winds, large hail, and some isolated tornadoes across Michigan, Indiana, and Kentucky (Figure 13). Michigan primarily had widespread wind damage, with gusts reaching up to 65 mph, and nearly 80,000 customers experienced power outages. There were 4 confirmed tornadoes in Indiana, and tragically, one resulting fatality. There were numerous reports of large hail ranging in size from 2-4 inches from nearly a dozen Indiana counties. Kentucky was affected by straight-line winds up to 110 mph, several confirmed tornadoes, and large damaging hail.
June 29 Derecho and Severe Weather
A damaging storm with widespread 70 mph winds moved southeast across Illinois and Indiana on June 29 (Figure 14). The storm downed trees and powerlines, damaged buildings, and caused extensive power outages. Several tornadoes were confirmed in Illinois.