Law and Public Safety

Law and Public Safety

St. Louis County Outdoor Warning Sirens

Typical St. Louis County outdoor warning siren.

The Emergency Communications Network is responsible for the maintenance and repair of the outdoor warning siren system located throughout St. Louis County.


The outdoor warning sirens are tested monthly, weather permitting, on the first Monday of the month at 11:00 AM.


What should you do when you hear the tornado sirens?

When you hear the sirens, you should SEEK SHELTER AND SEEK INFORMATION.

If you are outside, go to a pre-designated shelter area such as a safe room, basement, storm cellar, or the lowest building level. If there is no basement, go to the center of an interior room on the lowest level (closet, interior hallway) away from corners, windows, doors, and outside walls. Put as many walls as possible between you and the outside. Do not open windows.

Once you are inside and safe, turn on a TV, radio or NOAA weather alert radio to be informed of the storm location, path and the duration of the warning. There is no all-clear signal, once the warning has expired it is safe to leave your shelter location. Be aware, however, that the situation can change so be prepared in case another warning is issued for St. Louis County.

We strongly recommend that every residence, business and school use a weather alert radio with battery back-up. Weather alert radios automatically activate to warn and inform you whenever a warning is issued for St. Louis County.


Missouri Tornado Siren Video


What if I am in a vehicle, trailer or mobile home?

It is a good practice to check the weather forecast before leaving for work, school or simply running errands. if severe weather is in the forecast, make sure you continue to keep a radio tuned to a local station to keep informed of the weather situation as it develops.

If you are in a vehicle, trailer or mobile home, get out immediately and go to the lowest floor of a sturdy, nearby building or a storm shelter. Mobile homes, even if tied down, offer little protection from tornadoes.

If you are outside with no building available, lie flat in a nearby ditch or depression and cover your head with your hands. Be aware of the potential for flooding. Do not get under an overpass or bridge. You are safer in a low, flat location. Never try to outrun a tornado in urban or congested areas in a car or truck. Instead, leave the vehicle immediately for safe shelter. Watch out for flying debris. Flying debris from tornadoes causes most fatalities and injuries.

Whenever severe weather is possible, and you see any of the following signs:

Dark, often greenish sky
Large hail
A large, dark, low lying cloud (Particularly if rotating)
Loud Roar, similar to a freight train

Take Shelter immediately, do not wait to hear the outdoor warning system.

New Siren Information


As you may have seen in local media, St. Louis County has installed a new outdoor warning system. The new system has 195 sirens, most located at new sites to more efficiently cover the entire County population. The $7.5 million system is part of Proposition E-911, which was passed in November 2009. The $100 million bond issue will also replace individual police, fire and EMS communications systems, uniting them under one system.


If you have any questions about the siren system, contact the Director of the Emergency Communications Network (ECN), David Barney at 314-615-2562.

The sirens give instantaneous feedback on their functional status. This feature will reduce the amount of “down time” and provide for quicker repairs. Remember that the outdoor warning sirens are designed to be heard outside. The Office of Emergency Management still recommends that weather alert radios be used inside homes and business.

Siren Testing Information

The Countywide siren test is on the first Monday of every month at 11:00 a.m., weather permitting.

To report a siren that does not sound during the test and is in need of repair, you may send the information via e-mail to Mr. David Barney, Emergency Communications Network Director, or call (314) 615-2562


To report an unscheduled siren activation, do not e-mail. Call from 8:00 a.m. to 4:30 p.m. Monday through Friday at (314) 615-2562. After hours call St. Louis County Police Headquarters at (314) 889-2341.

Siren Activation Procedure

The St. Louis County Police Department will activate the outdoor warning siren system whenever the National Weather Service issues a tornado warning for St. Louis County OR a county adjacent to St. Louis County AND the direction of the storm path poses a threat to St. Louis County. If a tornado warning is subsequently issued for St. Louis County, the sirens will again be activated. This policy was created to provide more time for our citizens to gather information and seek shelter from severe and threatening weather.

If the tornado warning sirens are activated (a 3-5 minutes steady alert tone), individuals should immediately seek shelter, such as a basement, storm cellar, or the lowest building level.If there is no basement, go to the center of an interior room on the lowest level (closet, interior hallway) away from corners, windows, doors, and outside walls. Once you are in a safe room, check local television and radio broadcasts, or alerts issued by the National Weather Service (NWS) over a NOAA Weather-Alert Radio.

There is no all clear message sounded through the siren system. Listen to local media sources or a NOAA Weather-Alert Radio for information on the storms path.

Tornado Watches and Warnings

Warning the public of severe thunderstorms and tornadoes is the National Weather Service's most important job. To help the public prepare for tornado situations a tornado watch and a tornado warning program has been developed.

Tornado Watch:This means that conditions are favorable for tornado development. This is the time to prepare. You should keep alert by listening to radio, television or weather radio for the latest weather information. Know where your children are. Be aware of where you will go and what you will do if a tornado threatens.

Tornado Warning: This means a tornado has been sighted or indicated by radar. People in the path of the storm should take immediate life saving actions.