Back and Forth Temperatures, Resulting in Slightly Above Normal Temperatures for March

The average temperature for the Midwest was 37.6°F for March, which was 0.7°F above the 1991-2020 normal (Figure 1). While the Midwest monthly temperature was slightly above normal, temperatures throughout the month oscillated between warm and cold extremes week by week. This temperature “see-saw” resulted in 139 daily high maximum temperature records from March 1-7 (Figure 2) followed by 129 daily low maximum temperature records from March 10-13 (Figure 3). An additional 126 low maximum temperature records occurred March 22-31 (Figure 4). Statewide temperatures were mixed across the region, with temperature departures above normal across the lower Midwest and below normal across the upper Midwest. The monthly average temperature ranged from 3.4°F above normal in Ohio to 1.7°F below normal in Minnesota. Monthly maximum (Figure 5) and minimum temperatures (Figure 6) followed a similar geographic pattern.

Variable Precipitation across the Midwest

Average Midwest precipitation for March was 3.12 inches, which was 0.55 inches above normal, or 121 percent of normal (Figure 7). Precipitation was above normal for most of the Midwest, except for the extreme northwestern and southeastern portions of the region (Figure 8). Statewide precipitation totals ranged from 1.36 inches above normal in Illinois and Wisconsin to 1.33 inches below normal in Kentucky. Wisconsin had the 9th (tied) and Michigan had the 8th wettest March on record (since 1895). Green Bay, Wisconsin recorded its wettest March in 136 years with 6.03” for the month. A total of 16 stations across the Midwest set a new monthly maximum precipitation record for March while 489 daily high precipitation records were set or tied (Figure 9).

Snowfall Lingers through March

March snowfall in northwest Missouri and Kentucky ranged from 2-7.5 inches (Figure 10), which was up to 5 inches above normal for the month (Figure 11). Most of the Midwest, however, had near- or below-normal snowfall for March. Across the upper Midwest, monthly totals ranged from less than 1 inch in southern Minnesota to about 10-20 inches across the upper Great Lakes. A wide swath from southern Missouri to Ohio recorded less than 1 inch. There were 172 daily high snowfall records across the Midwest, with most from the lower Midwest where little snowfall typically occurs in March (Figure 12).

Drought Improvement

Drought conditions improved throughout March with reductions in both the intensity and spatial extent (Figure 13). By month’s end, 10 percent of the region was in moderate (D1) or severe (D2) drought with 19 percent abnormally dry. Drought and dry conditions were confined to the northwest portion of the Midwest with the largest affected area centered over southern Wisconsin.

Above Normal Precipitation Leads to Flooding

Above-normal precipitation paired with saturated soils resulted in periodic minor to moderate river flooding throughout March (Figure 14). The most affected areas included the Wabash River and tributaries in Illinois, Indiana, and Kentucky and also the Red River of the North in western Minnesota.

Notable Weather Events and Storm Reports

A tornado outbreak on March 5-6 affected Iowa, Illinois, and surrounding areas with over 60 reported tornadoes. In Iowa, three supercells produced 10 confirmed tornadoes, including an EF-4 tornado that killed six people and injured five others as it cut a 69.5-mile path through Madison, Warren, Polk, and Jasper Counties. Locations in Iowa saw hail sizes ranging from golf ball to baseball diameters. Twenty wind reports were in excess of 65 mph, and a peak wind gust of 81 mph was recorded at the Rockford, Illinois Airport. There were 64 tornado, 54 hail (48 reports were a minimum of 1” and 6 were greater than 2”), and 305 wind (28 reported greater than 65 KT) reports (Figure 15).