Iowa

Storm History: Johnson County, Iowa

528 episodes, 901 events since 1958

Every storm the National Weather Service has filed in Johnson County, Iowa: floods, hail, damaging wind, tornadoes, winter storms, heat and the rest, with the most serious on record. Events filed by forecast zone count for every county the zone covers.

The record

Events
901
Deaths
6
Injuries
71
Damage
$386 million
Episodes
528

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

Open the live radar over Johnson County

Every year

From 1996 the record holds 48 kinds of event with each office’s narrative; before that, tornadoes, hail and thunderstorm wind only, and before 1955 tornadoes alone.

By kind of event

Counted under the kind that heads each episode.

Kind of eventEventsDeathsInjuriesDamage
Tornado255151$71 million
Hail23312$2.7 million
Flash Flood10101$3.2 million
Winter Storm7303
Thunderstorm Wind51012$45 million
Winter Weather4100$5,000
Flood2500$231 million
Heavy Snow2301$15,000
High Wind1500$885,000
Ice Storm1500$1.0 million
Drought1500$31 million
Blizzard1300
Extreme Cold/Wind Chill1120
Dense Fog900
Frost/Freeze600$248,000
Cold/Wind Chill500
Heat400
Strong Wind100
Heavy Rain100
Excessive Heat100
Funnel Cloud100
Lightning101
Freezing Fog120

The deadliest

The costliest

Damage within this county, in the dollars of its year.

The largest hail

The largest stone in each episode, which may have fallen in a neighboring county of the same episode.

The strongest tornadoes

Every tornado in Johnson County, with its track

Every episode, newest first

Earlier years, state by state:

More

Tornadoes in Johnson CountyEvery warning in Johnson County since 1986Every county in Iowa

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24.