Weather Sirens in Dallas: What to Do When the Alarm Rings

Dallas has a network of 178 sirens that warn people about dangerous weather. They are not only for tornadoes but also for strong winds, large hail and other emergencies. The city follows five rules to decide when to sound the sirens: a tornado warning from the National Weather Service, a severe thunderstorm with 70‑mph winds or more, an on‑ground tornado in Dallas, hail that is at least 1. 5 inches wide, or any other emergency the city chooses to announce. The sirens are run by the Office of Emergency Management and Crisis Response. A common mistake is thinking they are meant to be heard inside houses or to wake people up. In fact, the sirens are loud outside and are meant to prompt people to find shelter quickly. If you hear a siren, do not call 911. The emergency office already has alerted first responders and city departments. Calling 911 would take away a line from someone who needs help right now. Instead, go inside, then check the city’s social media, local news or NOAA weather radio for details.The sirens are tested every month at noon on the first Wednesday. Other than that, they sound only when weather conditions meet one of the five criteria. Some residents feel they go off more often, but officials say the rules have stayed the same for about twenty years. Weather scientists predict that Texas storms will grow stronger as temperatures rise. The sirens are not all on at once. Dallas is split into six sectors, and only the sectors that need warning go off. If a storm moves or its threat changes, different groups of sirens may start later. Each alarm lasts about three minutes. Occasionally the whole city will sound all sirens if the entire area is at risk. Sirens are monitored through digital radio. If one fails, maintenance crews fix it right away, though parts may need to be ordered if the unit is damaged. Even when a siren is out, other nearby sirens usually cover the area. People should not rely on a single alert system; it is one tool among many.