Storm Warning Sirens

Johnson County Siren Guidelines

The storm warning sirens are an outdoor warning system, designed to alert those who are outside that something dangerous is approaching and to seek shelter inside. 

Under the Johnson County outdoor warning system guidelines, sirens are sounded for:
  • Tornadoes: Tornado warnings, either Doppler radar-indicated or reported by a trained spotter.
  • Wind: Severe thunderstorm warnings with winds of 70 mph or greater (potential for whole trees to snap or uproot).
  • Hail: 1.75 inch (golf ball-sized) or larger (potential for windows to break)

What to Do When a Siren Sounds

The storm warning is a high-pitched, constant tone that lasts for 3 minutes. Sirens may be sounded multiple times to convey a continued or new threat.  If sirens sound:
  • Seek immediate shelter indoors.
  • In the threat of a tornado, seek indoor shelter in a basement.
  • Stay away from windows.
  • Respond to the storm warnings provided by the National Weather Service. 
storm warning siren

Siren Testing


Sirens are tested on the first Wednesday of each month starting at 10:00 am and are operated by the Johnson County Joint Emergency Communications Center. 

Siren Locations


Outdoor storm warning sirens are located throughout Coralville (north and south of Interstate 80) to provide notification of severe weather.
  • Kiddie Korral Park (Intersection of 12th Avenue and 8th Street)
  • Coral Ridge Avenue (Highway 965) and Holiday Road (northeast corner)
  • Forevergreen Road and Highway 965 (shared with North Liberty)
  • 2000 James Street
  • 2500 Jones Boulevard
  • 1st Avenue at Brown Deer Golf Club entrance
  • 2351 Old Hospital Road (Oakdale Campus)
Most of Coralville’s storm warning sirens operate on solar charged batteries which allow the system to remain functional in the event of a power failure.  If you live near a siren and think it is malfunctioning, please contact the Fire Department at 319.248.1835.