Iowa City hail storm history
Johnson County·NOAA NCEI Storm Events Database·~75-day publication lag
Iowa City, located in Johnson County, has experienced 1 hail event of 1 inch or larger over the past 10 years. This relatively low frequency reflects eastern Iowa's position at the northern edge of the continental hail belt, where severe thunderstorms track primarily through the central Plains before moving northeast into the state.
Hail risk in Iowa City peaks during May and June, when organized mesoscale convective systems and squall lines from the central Plains track northeast across the region. Secondary activity occurs in April and July, with derecho events also common through this corridor during summer months.
Annual frequency — last 10 years
When hail hits — monthly pattern
Avg events per month · all years · NOAA data
All recorded hail events
Of 150 recorded events, 30 (20%) reached 1.5" or larger — the threshold for likely functional damage on standard asphalt shingles.
Time estimated by radar.
Reported via Mping.
Spotter also reported 40 to 50 mph winds.
Public report of 1 inch hail east of Kalona.
Ping pong ball size hail fell for 10 minutes.
This public report was received through social media.
Report received from Mping.
Report from Mping.
Trained spotter reported that hail was occurring at the moment of the report.
A public report of hail increasing in size to 1 inch. Also reported that sheet metal and insulating …
Time estimated using radar.
Amateur radio operator relayed the report from the fire chief.
A HAM radio operator reported dime to quarter sized hail.
Received a public report of three quarter inch hail.
CBS2 Meteorologist storm chasing reported lots of quarter size hail and few half dollar size.
Penny size hail was reported.
Quarter to golf ball sized hail lasted 5 minutes.
The reported arrived from social media.
A public report was received of penny sized hail.
Received an amateur radio report of nickel sized hail six miles southwest of Washington on Highway 1…
A trained spotter reported hail up to the size of 1 inch in diameter.
The time of the event was estimated using radar.
Pictures of hail the size of quarters received via the KCRG Facebook page.
The county emergency manager reported pea to dime sized hail on the east side of Iowa City at 7th an…
A picture from the public of hail was received via Twitter. The time was estimated from radar.
A public report was received of quarter sized hail, also winds up to 55 MPH and heavy rain.
The public reported many hailstones the size of nickles with a few stones the size of quarters that …
A trained spotter reported quarter size hail.
A spotter reports 1.25 to 1.50 hail falling along Interstate 80.
Spotters reported nickel size hail. The time was estimated from radar data.
Trained spotters reported 5 to 6 minutes of dime size hail.
Johnson County's documented hail record includes 2 events of 1 inch or larger in the NOAA Storm Events Database, with none reaching the 1.5-inch threshold associated with significant structural damage. The low event count reflects both genuine storm frequency and NOAA's reporting density in rural areas—not all hail events are captured in official records, particularly smaller events in sparsely populated zones. Current-year data is excluded from the annual frequency table until October, when NOAA's Storm Events Database has processed the full hail season accounting for the standard 75-day reporting lag.
NOAA Storm Events Database source