Outdoor Warning Siren System – Severe Weather Alerting

Outdoor Warning Siren System – Severe Weather Alerting

The Village of Oak Brook operates 4 outdoor warning sirens, which are strategically placed throughout the Village. These sirens form an overlapping pattern to effectively alert the public to emergencies such as severe weather emergencies.

The Village tests its outdoor warning sirens at 10:30 a.m. the first Tuesday of each month, so if it's testing time and the weather is clear, it's just a test. 

What to do if you hear a siren: 

  1. Be alert. The severe weather warning siren consists of a 3 minute steady siren blast. 
  2. Seek shelter immediately. 
  3. Turn on your radio for further information. 

Note: Residents should NOT call 9-1-1 to find out why sirens are sounding. Only dial 9-1-1 if you need to report an emergency.

Important: The Village does NOT sound an "all-clear" signal. If the sirens are activated again, it generally is because a new threat or warning has been issued. A secondary activation does not mean it is safe to come out of shelter areas. 

The purpose of outdoor warning siren system is designed to be heard outside. The system is not intended to penetrate inside residential and commercial structures. Warning sirens only have an audible footprint of one to two miles, meaning that you have to be within that distance (in any direction) of the siren in order to be able to hear it. Keeping that in mind, during the rain and hail that oftentimes accompanies many severe storms, it becomes even harder to hear a siren at a distance. Wind speed and direction also will affect that sound range. 

Outdoor warning sirens exist for one purpose only – To alert people who are outdoors that something dangerous is happening, and that they should go inside. Once inside, people should use a radio or the television to get current and updated information. 

Ultimately, while outdoor warning sirens can be instrumental in warning citizens who are outdoors about impending danger, residents who are already inside need to depend on other options to stay updated on impending danger. 

Indoor warning siren options -- if you are indoors, use a radio, television or a special National Oceanic and Atmospheric Administration (NOAA) weather radio to get specifics on potentially dangerous weather events. Like a smoke detector, a weather radio waits in standby mode until a warning is issued. When the National Weather Service issues a warning, weather radios in businesses and households throughout the threat area automatically alarm and broadcast the warning, allowing people to take the appropriate actions. Portable models also are available for use outdoors or when traveling.

Wireless Emergency Alerts contain potentially life-saving information.

Be sure your mobile device is enabled to receive them.  The alerts are sent out by authorized government authorities.  The National Weather Service and other agencies send out wireless alerts when a tornado, flash flooding, evacuation order or other immediate emergency is happening.

But how do you make sure your cell phone other mobile device is set up to receive them?

First, it is important to note the distinction between these types of messages, known as Wireless Emergency Alerts, and others that you might sign up for through apps or other sources. WEAs are sent by authorized government alerting authorities such as the NWS, FEMA, the Department of Homeland Security and local and state public safety agencies. They are distributed to all phones within a certain radius of the emergency, so you will receive them for whatever local area you are in.

The alerts are short and contain basic information.
Here is an example of a Wireless Emergency Alert warning of hazardous weather conditions:

(National Weather Service)
A WEA for a tornado warning, for example, typically reads, "NWS: TORNADO WARNING in this area til 12:15PM CST. Take shelter now. Check media."

You do not have to enroll or download anything to get WEAs, but your phone does need to be enabled to receive them.  Please check with your mobile telephone provider for additional information on how your device can be setup.