Lewisville Citizen Alert is an emergency notification system used to make rapid emergency notifications to residents and businesses in the city of Lewisville. The system is used by Lewisville emergency officials to deliver severe weather notifications and incident-specific information or potentially life-saving instruction to those in the affected area(s). This system enables the City to deliver important messages to our residents and businesses via phone call, text message, or email.

The Outdoor Warning System in the City of Lewisville consists of 16 sirens strategically placed throughout the city. The sirens are sounded when there is a dangerous situation outside. We stress that the Outdoor Warning System is primarily intended to warn people who are outdoors, so that they may seek shelter and seek information. To watch a video to hear what the Outdoor Warning Sirens sound like visit our YouTube Channel.

Thor Guard Lightning Detectors can predict lightning before it strikes. Thor Guard Lightning Detectors continuously monitor the atmosphere's electrostatic energy and evaluates the potential for lightning (97% accurate within a 2-mile radius, with detection possible up to a 15-mile radius), and when a detector determines the potential for lightning in the area a 15-second air horn blast will sound and its strobe light will turn on. Upon hearing or seeing these signals people who are outdoors should seek appropriate shelter. When the detector senses conditions are safe, the strobe light will turn off and the horn will sound three short 4-second blasts. Then normal activity may resume. To watch a video to hear what the Thor Guard Lightning Detector siren alert tone sounds like visit our YouTube Channel.

Thor Guard Lightning Detectors are installed at City parks and aquatic facilities, Lewisville Independent School District campuses, and at City Hall.

The National Oceanic and Atmospheric Administration (NOAA) All-Hazards Radios are used nationwide, and broadcast weather information directly from the National Weather Service from a nationwide network of radio stations. During dangerous weather, they are activated automatically by the National Weather Service when the weather threatens a certain area. The Lewisville Office of Emergency Management highly recommends that you purchase an All-Hazards Weather Radio with the programmable alert feature (using S.A.M.E. technology), and program it accordingly to deliver weather warnings when issued for our area. These are excellent tools for ensuring your household has a means of receiving weather emergency warnings, especially during night time.

• Denton County: 048121
• Dallas County: 048113
• Tarrant County: 048439
• Collin County: 048085