Monthly Overview - April 2020

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Varied Precipitaiton

Similar storm tracks across the Midwest in April left some areas very wet while others dry (Figure 1).  For the month, regional average precipitation was 2.91 inches which was 0.42 inches below normal.  Storms impacted Illinois, Kentucky, southern Missouri and Michigan, leading to amounts moderately to in some cases well above normal.  Heavy rain impacted Illinois during the final week of April (Figure 2) to add to near-normal precipitation prior.  More than 250 daily precipitation records were broken across the Midwest in April (Figure 3).  Meanwhile, most of Iowa, Minnesota, southern Wisconsin and Indiana had less than 75 percent of normal (Figure 4).  Northern Iowa and southern Minnesota had less than 50 percent of normal.  Iowa precipitation was ranked 15th driest on record for April (1895-2020).
 

Widespread Chill

Temperatures were well below normal across the Midwest in April (Figure 5).  Midwest average temperatures were 46.0°F which was 3.0°F below normal. After a warm first week across the region, temperatures shifted colder through mid-month.  Exceptionally cold temperatures for April were observed from April 15-21, with widespread freezes on the mornings of April 15 (Figure 6) and April 16 (Figure 7).  Of the more than 800 daily low temperature records broken or tied across the region in April (Figure 8), more than 300 of these occurred on April 15 and April 16.
 

Upper Midwest Snowfall

Colder temperatures allowed for several major snowstorms in April (Figure 9).  In total, more than five inches fell across southern Iowa, southern and northwestern Minnesota, and northern Wisconsin.  Amounts over 12 inches fell in the U.P. of Michigan.  Most of the snowfall from southern Iowa through northern Ohio fell from April 15-18 (Figure 10), while storms on April 3-4 (Figure 11) and April 11-13 (Figure 12) dumped snow on Minnesota, Wisconsin and the U.P. of Michigan.  The heavy spring snowfall led to more than 240 daily snowfall records across the region (Figure 13).
 

Severe Weather

Severe weather across the Midwest intensified in April, with more than 850 reports of hail, strong winds and tornadoes.  A widespread outbreak on April 7 (Figure 14) and April 8 (Figure 15) caused strong winds and hail from Illinois through the Ohio River Valley.  Wind gusts exceeding 75 mph were reported as power outages were caused in Illinois from toppled power lines and trees.  Several weak tornadoes were also reported.  Strong winds also impacted southern Missouri on April 28 (Figure 16).
 

Drought-Free Period Continues

Drought remained non-existent in the Midwest in April (Figure 17).  All four of the U.S. Drought Monitor updates remained free of drought, bringing the streak of drought-free conditions to 25 consecutive weeks.  However, drier weather in west-central Minnesota and Lower Michigan led to the introduction of abnormally dry conditions in the April 21 U.S. Drought Monitor.  This broke a streak of 14-consecutive weeks without abnormally dry conditions in the Midwest.
 

Frost/Freeze Damage

Minor frost and freeze damage were reported from freezing temperatures on April 15 and April 16.  Early planted vegetables suffered damage in Illinois and Indiana.  Michigan also reported minor damage to apple trees and grape vines as temperatures were well below freezing.
 

Planting Season Begins

As soils dried out in April, optimism for planting season grew across the Corn Belt.  Planting slowly began in the southern Midwest during the second half of April, with significant planting occurring through the week ending April 26.  Corn planting was at 35 percent or higher in Kentucky, Illinois, Iowa and Minnesota according to USDA’s National Agricultural Statistics Service (Figure 18).  Only Missouri was significantly behind at 21 percent below their five-year average.   Soybeans were also being planted, with Kentucky and Illinois both at 18 percent planted (Figure 19).  Motivation to plant was increased in Illinois leading up to a storm system that brought heavy rain on April 29-30 and significantly increased soil moisture.
 

Spring Flooding

Minor flooding was sporadically reported along the Mississippi River in April (Figure 20).  Heavy rain in March coupled with high soil moisture increase susceptibility for flooding along the river through mid-April.  Flooding also impacted several rivers in Illinois from a storm on April 29-30 (Figure 21).  Minor flooding was reported with some moderate flooding along the Illinois River south of Peoria, IL.
 

-BJP-