An intense derecho affected much of the Midwestern United States on August 10–11, 2020, primarily eastern Nebraska, Iowa, Illinois, Wisconsin, and Indiana.

[19] These convectively unstable conditions permeated across Iowa and were characterized by steep lapse rates in the mid-levels of the troposphere as sampled via weather balloon launches from Omaha, Nebraska, on the morning of August 10, and from Davenport, Iowa, at noon that day;[24][25] the atmospheric sounding retrieved from the Davenport balloon launch observed lapse rates of 8.5 °C/km.

These storms tracked east along the South Dakota–Nebraska border and became better organized and coalesced, producing hail with diameters between 1–2 in (25–51 mm) and wind gusts between 60–70 mph (97–113 km/h) over a narrow swath.

Heating associated with the daytime hours made for warmer conditions near the ground, allowing strong winds produced by the storms to descend to and reach the surface.

Over the next two hours, the storm traversed central Iowa with a rapid forward speed of up to 60 mph (95 km/h), impacting communities including Ames, Des Moines, and Marshalltown.

[30] Aloft, the storm was being supported by a rear-inflow jet sporting winds of 80–100 kn (90–115 mph; 150–185 km/h) with the downwind airmass exhibiting convective available potential energy (CAPE) values between 2000–2500 J/kg.

[33] At 11:25 a.m., a severe thunderstorm watch tagged as denoting a particularly dangerous situation was issued by the SPC for areas ahead of the storm including central Iowa, southern Wisconsin, northern Illinois, and northwestern Indiana.

Based on the severity of damage observed, the NWS estimated that wind gusts of 130–140 mph (210–230 km/h) impacted parts of Benton and Linn counties in Iowa, including downtown Cedar Rapids and Marion.

[3] The financial toll of this storm was the second-highest for an individual 2020 U.S. natural disaster,[VI] surpassed only by Hurricane Laura's preliminary damage figure of $14.1 billion.

[46][39][14] Terry Dusky, chief executive officer of electrical infrastructure company ITC Midwest, described the storm damage as "...equivalent of a 40-mile wide tornado that rolled over 100 miles of the state.

[66][67] Emma Hanigan, an urban forester for the Iowa Department of Natural Resources, said that the impact on the state's trees will be felt for decades.

[76] Cedar Rapids, Iowa, the Linn County seat and second-largest city in the state, was one of the hardest hit areas of the storm.

[15][9][10] Adjutant General Benjamin Corell, Commander of the Iowa National Guard, compared the extent of the damage with what he personally witnessed after Hurricane Katrina.

[88] Almost every structure within the 75 square miles (190 km2) Cedar Rapids city limits, including residences, 20 schools, and businesses, were damaged in some way, much of it severe, some of it catastrophic.

[90][91] By September 4, 2020 utility workers had installed over 3,400 new poles along with 400 mi (640 km; 640,000 m) of wiring in the Cedar Rapids area after repairing most of the main electrical infrastructure in the city.

[92] On November 9, 2020 Dr. Melanie Giesler, a local physician, said increased allergies in the area were likely due to the derecho damage, spurred on by dust, debris, and mold growing on dead plant matter.

[93] In July 2022, The Gazette reported that nearly two years after the derecho, owners of homes with historic preservation concerns were still repairing antique windows damaged by the storm.

[100] A Hy-Vee grocery store there was found by the Iowa Department of Natural Resources to have illegally dumped 800 US gallons (3,000 L) of spoiled milk into storm sewers, contaminating a local waterway.

[107] Marshalltown Veteran's Memorial Coliseum, a historic city sports venue, is reopening soon as of November 30, 2020[update] after being severely damaged by the 2018 tornado and later impacted by the derecho.

[114] In the week after the storm, Iowa elected officials such as US Senators Chuck Grassley and Joni Ernst, US Representative Abby Finkenauer, and Governor Kim Reynolds called for and worked to secure a federal disaster declaration from President Donald Trump.

[63] The following day, Trump announced he had partially approved Reynolds's request, but did not approve the requested FEMA Individual Assistance Program, which Reynolds's office says "provides disaster-impacted homeowners and businesses with programs and services to maximize recovery, including assistance with housing, personal property replacement, medical expenses and legal services".

[133] Local non-profits told Iowa's senators that assisting the region has been difficult due to the COVID-19 pandemic significantly reducing their donations and funding.

[131][138][139] Many grassroots efforts began hours after the storm subsided, with residents lending support through mutual aid, and trying to take care of the least fortunate, but finding working with government and assistance organizations very disheartening.

[121] Tamara Marcus, activist with Cedar Rapids Advocates for Social Justice, a Black Lives Matter organization, said "We need to ask ourselves, 'Why is it that each time we have a disaster or pandemic, the most-vulnerable are the worst impacted, particularly communities of color?'

[121] Residential damage doubled the homeless population in the Cedar Rapids area as some landlords evicted residents from unsafe apartment complexes.

[140][141] Abby Finkenauer, then-US Representative for Iowa's 1st congressional district (which encompassed Cedar Rapids and other hard-hit areas), used her local office for an assistance event, personally handing out essentials such as food, water, and toiletries until supplies ran out.

The Democratic Congressional Campaign Committee returned the criticism, saying that while Hinson had released a stereotypical ad and posed for storm-related photo ops, Finkenauer actually worked on doing something meaningful at the time.

[143] Climate change is a possible cause of the intensity of derechos overall, said Iowa State University and National Weather Service (Des Moines) scientists; experts disagreed if it was responsible for this particular storm.

[144][145] The high damage estimate aligns with analysis showing increases in the costs of natural disasters as a result of climate change-driven storm intensity.

[3][146] The Storm Prediction Center (SPC) did not initially foresee an event of this magnitude, primarily due to sporadic model solutions, more specifically the large variance in intensity, location, and coverage of this derecho.