Outdoor Warning Sirens
Outdoor Warning Sirens
Outdoor Warning Sirens (commonly called “tornado sirens”) may be the most instantly recognizable method of public warning currently in use. Though nearly everyone has heard them, not everyone understands what they mean – especially because siren policies can differ from county to county. Understanding when, why, and how sirens are used in Johnson County can directly affect the safety of individuals and families when quick action is necessary.
Most of the warning siren units are powered by batteries charged by solar panels. The cost of installing a siren now ranges between $30,000 and $50,000. Seventy-three units were installed and are maintained by Johnson County Emergency Management, and the rest were installed and managed by local municipalities.
Though nearly everyone has heard them, not everyone understands what they mean – especially because siren policies can differ from county to county. Understanding when, why, and how sirens are used in St Charles County can directly affect the safety of individuals and families when quick action is necessary.
> View the location of the outdoor warning sirens throughout Johnson County.
Warning sirens are activated when a tornado warning is issued or there is a visual confirmation of a tornado in Johnson County.
The goal for these warnings is to alert residents and visitors that a hazard exists and to signal the need to obtain further details about the situation. When residents hear a siren, they should:
- Quickly observe conditions around them.
- If there is a visible threat, immediately take cover in the safest structure available.
- If there is no threat visible, go inside to a safe location and tune to broadcast media, NOAA Weather Radio, or the internet for specific information about the danger.
Warning sirens are not designed to be heard indoors.
They are designed to warn anyone outside to move indoors to a safe place and to obtain further details about the situation. Even if sirens are normally audible inside the home, noise from wind, thunder, or hail can prevent occupants from hearing during severe weather. As a precaution, residents are strongly urged to have more than one source for emergency alerts and information inside the home.
Johnson County does not automatically activate warning sirens whenever a warning is issued in an adjacent county.
Johnson County policy is to activate sirens when a warning is issued for an area within the county. If a threat in an adjacent county is close and moving toward the county line, JCCD may activate sirens to ensure our residents have time to act.
Warning sirens do not sound “all clear” signals.
If you hear sirens sound more than once, that means that another warning or danger to public safety exists. Please take precautions and obtain more information to protect yourself and others from this additional threat.
Warning sirens are tested regularly to ensure they will function properly in an emergency. On the first Wednesday of each month at 10:00 a.m., sirens are tested. Additionally, alert receivers and informers are tested silently every Wednesday.
How to Report Malfunctioning Warning Sirens
Warning sirens can malfunction for various reasons. If you notice that a siren doesn’t appear to be working properly, let us know. Please contact Johnson County Central Dispatch at 660-747-2265 or Johnson County Emergency Management Agency at 660-747-2666.