Outdoor Warning Siren Systems

Many communities have installed outdoor warning siren systems to provide additional warning of impending danger.  As their name implies, these sirens are intended to be heard outside. The system is not designed or engineered to be heard inside every building in the coverage area.

Since the early 1960s, the cities of Charleston and Mattoon have maintained an Outdoor Warning Siren System to warn the residents of approaching tornadoes, major emergencies, or the possible threat of an attack on the United States. These sirens are tested the first Tuesday of each month at approximately 10 a.m. The test consists of one and a half minutes of a steady tone, one minute of silence, and one and a half minutes of a wavering tone. Eastern Illinois University also has a warning siren on campus which is tested at the same time. The EIU siren has only the steady tone.  The Coles County Emergency Management Agency (EMA) activates or authorizes activation of the outdoor siren systems.

During an emergency activation, the steady tone is used to alert the public that a tornado has been sighted and is approaching the community, this tone will last three to five minutes. When the steady tone is heard during severe weather, you should seek a place of shelter immediately. If the steady tone is heard at any other time, it is a signal that an emergency is occurring in the community and you should tune to local Cable TV or radio stations for information on the emergency. During severe weather or an emergency situation, the Coles County EMA may pre-empt MediaCom Cable TV programming to provide information on the storm or emergency situation using a voice message system.

The wavering tone is used only as a take cover signal of imminent danger of a nuclear attack on this country.

If you hear the outdoor warning sirens at any time other than on test day,  do not call the 911 Center,  Fire Department, Police Department or EMA Office unless you have a real emergency.  At anytime severe weather threatens on siren test day, the outdoor sirens will not be tested to avoid confusion. If you hear the sirens sounding a steady blast of three to five minutes duration on test day, that indicates an emergency, seek shelter immediately. During Icy weather conditions, the sirens will not be tested to avoid damage to the systems.


Often people believe that the sirens are sounded after an emergency has passed to indicate an "all clear." Coles County DOES NOT issue an "all clear" by activating the sirens. For information on the emergency, including when conditions are no longer threatening, your best source of information is your radio or television.  For any questions concerning this information, please call Coles County Emergency Management at  (217) 348-0581. 

Alert Radio System

The Emergency Management Agency (EMA) maintains an Alert Radio System that is used to provide severe weather and special emergency/disaster information as it pertains to the cities of Charleston and Mattoon. The radios have been installed in all schools, the hospital, most nursing homes and municipal offices. The alert radio system is available to anyone. Information on the alert radios or any aspect of emergency preparedness can be obtained by calling the Emergency Management Agency at (217)-348-0581.

520 Jackson Avenue, Charleston, IL 61920 ~ Phone 217-345-5650 ~ TTY 217-345-7517 ~ Fax 217-345-7554 ~ cityhall@co.coles.il.us