Temperature

The average April temperature for the Midwest was 48.8°F, 0.1°F below the 1991-2020 normal (Figure 1). Statewide average temperatures ranged from 3.6°F below normal in Minnesota to 1.9°F above normal in Michigan. April was marked by significant temperature swings across the region. Most notable was the warmup that sent temperatures soaring across the Midwest from April 8 – 16. High temperatures on April 12 and April 13 were up to 25°F above normal across the upper Midwest, and up to 10°F above normal in the lower Midwest (Figure 2). Sioux City, Iowa reached 92°F on April 12th, which tied for the 6th highest April temperature since record-keeping began in 1896. Numerous long-running stations in Wisconsin, Minnesota, and Michigan recorded four consecutive days with temperatures at or above 80°F, setting a record for the most number days at or above 80°F during the first half of April. A cold front traversed the region on April 16 ushering in colder-than-normal temperatures that would linger for the rest of the month. By April 17, temperatures across the northern and central Midwest were 50-60°F cooler than at the peak warmth just 1-3 days prior. During the last week of April, minimum temperatures in the low to mid 20s were observed, even in the southernmost areas of the region, which led to frost advisories and freeze warnings. Demonstrating the extreme variability in temperatures, 1,074 daily warm temperature records (Figure 3) and 588 daily cold temperature records (Figure 4) were set during the month of April.

Precipitation

April precipitation totaled 2.81 inches for the Midwest, which was 0.86 inches below normal, or 77 percent of normal (Figure 1). Across the region, monthly precipitation anomalies were below normal in the lower Midwest and well above normal in the upper Midwest (Figure 5). Statewide precipitation totals ranged from 2.89 inches below normal in Missouri to 0.77 inches above normal in Wisconsin. Medford, Wisconsin, accumulated 6.37 inches in April, which was the wettest April in 131 years of observations. Marquette, Michigan had its wettest April in 147 years with 6.63 inches of precipitation. Conversely, Columbia, Missouri had its 2nd driest April in 134 years with just 0.58 inches of precipitation recorded.

Snow

Snowfall totaled 5-40 inches across most of Minnesota, Wisconsin, and Michigan’s Upper Peninsula during April (Figure 6), which was significantly above normal for these areas (Figure 7). High snowfall was fueled by multiple snowstorms throughout the month. There were 180 daily high snowfall records broken or tied for the month, with most happening in Minnesota and Wisconsin (Figure 8). Phelps, Wisconsin, located in the north central region of the state, had the snowiest April in 106 years with 34.1 inches of snow. Above-normal snowfall during April resulted in Duluth, Minnesota achieving its highest seasonal snowfall in 133 years (2022-23 snowfall was 140.1 inches as of April 30).

Drought

Just over 80 percent of the Midwest was free of drought or dryness during April, mostly east of the Mississippi River (Figure 9). In the west, drought and dryness persisted or expanded. Iowa continued to be the epicenter of drought in the region, with about 30 percent of the state affected by moderate (D1) to exceptional (D4) drought and about 30 percent listed as abnormally dry. Conditions worsened in Missouri, with about 11 percent of the state in drought by month’s end, up 9 percent from last month. In Minnesota, dryness lingered in about 40 percent of the state while D1 affected just over 1 percent.

Flooding

An unusually warm early- to mid-April prompted rapid snowmelt of a deeper-than-normal snowpack in the upper Midwest. This, subsequently, led to near-record flooding along the upper Mississippi River that persisted through the end of the month. Numerous river gauges along the Mississippi River in Minnesota, Wisconsin, Iowa, and Illinois ended the month in major flood stage (Figure 10). Communities along the river implemented various measures including voluntary evacuations, pumping water, sand bagging, and fortifying flood walls to manage the flood waters. Boats and barge traffic were halted above St. Louis, Missouri due to flooding and lock closures along the upper stretches of the Mississippi River.