Outdoor Warning Sirens

For St. Charles County residents, St. Charles County Regional Emergency Management offers this list of Five Facts Emergency Managers Want You to Know About Outdoor Warning Sirens.

1. Warning sirens are activated when a tornado warning is issued or there is visual confirmation of a tornado in St. Charles 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 internet for specific information about the danger.

2. Warning sirens aren’t 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.

3. St. Charles County does not automatically activate warning sirens whenever a warning is issued in an adjacent county.

St. Charles 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 enough, and moving toward the county line, Emergency Management may activate sirens to ensure our residents have time to act. That decision is made on a case-by-case basis.

4. When the sirens are activated, normally they are activated county-wide.

Sirens have been purchased over many years, from various manufacturers and by different jurisdictions. As the cities and county grew, the sirens have been linked to form the current siren network. With the current system, it has been determined that selecting and grouping the correct sirens for the specific area under warning would be slower and less efficient than activating the entire system that alerts our entire county. 

5. 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.