Cold North, Warm South
After an exceptionally cool third week of April, northern areas stayed cool while southern areas turned warm in the final week of the month
(Figure 1). Most of Minnesota, Wisconsin and northern Michigan were 2-6°F below normal, while southern Iowa, Missouri and western Illinois were 2-6°F above normal. Some areas in the Ohio River Valley were 1-3°F above normal as well.
Wet South, Dry North
Moderate to heavy rain fell across southern Missouri and the Ohio River Valley during the week, with little rain in the northern half of the region (Figure 2). Areas in southern Missouri received 3-5 inches with most of the Ohio River Valley receiving more than an inch. While some moderate rain fell across the southern half of the region through the mornings of April 24
(Figure 3) and April 25 (Figure 4), most of the precipitation fell through the morning of April 29
(Figure 5). Isolated areas in extreme southern Missouri received more than five inches. Rain continued in the Ohio River Valley through the morning of April 30 as well (Figure 6). In total, more than 70 daily precipitation records were broken across the region
(Figure 7). The Upper Midwest was much drier in contrast. Most of Iowa and southern Wisconsin had less than a quarter of an inch during the period. Most of Iowa, southern Wisconsin and central Lower Michigan had less than a quarter the normal amount (Figure 8). However, areas in northern Michigan were an outlier in the Upper Midwest, with more than twice the normal amount during the period.
Drought Expands into Wisconsin, Iowa, Minnesota
Increasingly dry conditions ahead of the start of planting season in the Upper Midwest led to an increase of drought across portions of southern Wisconsin, northeastern Iowa and southeastern Minnesota in the April 27 U.S. Drought Monitor
(Figure 9). Many stations in these areas had one of their driest Aprils on record. Soil moisture was measured short or very short in more than a quarter of Iowa and Minnesota and was 21 percent in Iowa according to USDA NASS, which was a contributing factor.