Cedar Rapids, Iowa City and Waterloo: Derecho Winds, Hail and Who Fixes What

Linn County's derecho entry

NOAA's Storm Events Database logs the Linn County derecho as one thunderstorm wind event lasting from 11:30 a.m. to 12:50 p.m. CST on August 10, 2020, with an estimated magnitude of 122 knots, roughly 140 mph. The entry records one death, a 63-year-old man on a bicycle struck by a falling tree, and 100 injuries.

The same entry estimates 80 to 100 mph winds for much of the county and 120 mph or more in central Linn County. Damage to a Cedar Rapids apartment complex indicated winds of about 140 mph, a radio tower collapsed under winds estimated at 130 mph, and the Cedar Rapids airport sensor measured 68 mph before it lost power.

Reports on the Storm Prediction Center's log for the day read like a work order: a house roof nearly torn off near Hiawatha, part of a church roof ripped away near Marion with shingles missing, and an athletic building west of Cedar Rapids with two walls blown out.

Johnson County: lower gusts, the same repair list

NCEI's Johnson County derecho entry is estimated at 70 knots, with 60 to 80 mph winds across much of the county and 80 mph or more in the north. The Iowa City airport measured 69 mph before its power failed. The SPC log adds an 80-foot tree snapped near Coralville and minor damage to new construction east of Iowa City.

Johnson County's worst structural damage in recent years came from tornadoes. On March 31, 2023, an EF2 near Hills tore roofs completely off and stripped siding from several homes, and a second EF2 at Coralville lifted part of a retail building's roof and flipped trailers.

Ten years of storms in three counties

NOAA's Storm Events Database records these counts for 2016 through 2025 (NCEI):

Linn County's largest stones in that window measured 2.75 inches, at Hiawatha on April 7, 2020 and near Fairfax on July 11, 2020. In Black Hawk County, a trained spotter reported 3-inch hail at Evansdale on June 24, 2023, and 2.75-inch hail was reported in Waterloo the same day.

FEMA declarations along the corridor

Linn and Johnson counties are both designated under DR-4557, the 2020 derecho declaration. Black Hawk, Johnson and Linn share DR-4187 for the June 2014 severe storms, tornadoes, straight-line winds and flooding, and Linn and Black Hawk appear together in the 2016 flooding declaration, DR-4289.

The largest single loss in Linn County's NCEI file is still water, not wind: the June 2008 Cedar River flood crested at 31.12 feet in Cedar Rapids on June 13, 2008, against a 12-foot flood stage, with damage in the city estimated at no less than $750 million.

Hiring here

A wind event like 2020 can put four crews on one house: a tree service to clear limbs, a roofer, a siding or window contractor, and often a water mitigation team for wet ceilings. Every one of them falls under Iowa's contractor registration, and subcontractors are not covered by the general contractor's number. Check each name with the contractor lookup on DIAL's contractor registration page before you sign, and read the registration rules on this site's home page.

Find roofers in Cedar Rapids, Iowa City and Waterloo on the National Roofing Directory, and follow current alerts on its Iowa storm center.

Roofing companies in Cedar Rapids, Iowa City and Waterloo are listed on the National Roofing Directory.

Frequently asked questions

How strong were the derecho winds in Cedar Rapids?

NOAA's Linn County entry estimates 122 knots, about 140 mph, with the strongest damage at a Cedar Rapids apartment complex. The highest measured gust nearby was an unofficial 126 mph at Atkins in Benton County, according to NWS Quad Cities.

Was Iowa City part of the 2020 derecho declaration?

Yes. Johnson County is a designated area under FEMA's DR-4557 alongside Linn County. NOAA estimates Johnson County's derecho winds at 70 knots, lower than Linn's, with stronger winds in the northern part of the county.

Do subcontractors on my job need their own Iowa registration?

Yes. DIAL states that subcontractors are not covered under the general contractor's registration, and out-of-state subcontractors also need their own bond. Ask for every registration number on the job, not just the one on the contract.