Warning Sirens


Warning System will be activated when:

  • Deemed necessary by City of San Marcos officials (i.e. in the event of any emergency when officials need to get citizens to move indoors for their safety)
  • Hail of 1.25 inches (Half Dollar) in diameter is imminent
  • The National Weather Service issues a San Marcos area Tornado Warning or Severe Thunderstorm Warning with destructive winds at or above 70 miles per hour
  • Trained storm spotters have reported a tornado with the potential to affect the City of San Marcos


The City's outdoor weather warning system has 14 sirens that alert people who are outdoors to seek shelter in the event of a tornado. The system is tested as needed and advertised at Noon weather permitting. We do not test the sirens if the weather is bad or threatening; this helps to ensure that there will be no confusion as to whether it is a test or a real alert. The main purpose of the sirens is to warn individuals that are outdoors to seek immediate shelter. Since many outdoor sounds, including the weather sirens, cannot penetrate many buildings, the sirens are not intended to be heard while indoors.

During an Emergency

In the event of a Tornado Warning residents will hear a 3 to 5 minute steady signal of the sirens. When you hear the sirens during bad weather, go indoors and seek shelter in the most interior room in your home or office. You should avoid the outside walls and windows. An interior bathroom, closet, or other room is generally the safest location. Cover yourself with pillows or get under heavy furniture for protection. If you have access to a radio or television, turn it on to a local channel to listen for essential emergency information. All local channels will interrupt programming to issue Tornado Warnings and advise you where the tornado is located. Please do not call local fire or police agencies to ask why the sirens are sounding unless immediate assistance is needed.

If You Are Outdoors When the Sirens Go off

If you are outdoors when the outdoor warning sirens are activated seek shelter immediately. If shelter is not available and severe weather is in the area lie in a ditch, ravine, culvert or low-lying area. Make sure that the low-lying area that you choose is not prone to flooding. Use your arms or a piece of clothing to protect your head and neck.

If You Are in a Mobile Home or a Vehicle

Mobile homes and vehicles are extremely vulnerable to the effects of tornadoes and severe thunderstorms. One-third of tornado deaths nationwide occur in mobile homes. Residents of mobile home parks should have a designated shelter in the community or a plan for residents to evacuate to an off-site shelter location. Find out about the tornado shelter plan in your community. If there is no time to get to shelter, abandon the mobile home or vehicle and lie flat in the nearest ditch or depression with your hands covering your head. Never try to outrun a tornado.