Outdoor Warning System

Early Warning SirenOverview

McKinney's Outdoor Warning System (OWS) is designed to notify residents and visitors of potential hazards, weather and other emergencies. The system is maintained by the McKinney Office of Emergency Management and comprises 25 sirens strategically located throughout the city to sound alerts.

The city may set the sirens off during potential hazards, such as severe weather and other emergencies. The City of McKinney may make the decision to set off the sirens for severe weather based on information received from the National Weather Service and the threat to our community.

City of McKinney OWS Sirens Criteria for Activation

  • When a severe thunderstorm warning has been issued by the NWS predicting hazardous conditions such as large hail (1 ½ inches or greater based on storm history and trained spotter verification), destructive winds (73 mph or higher), or other hazards requiring immediate protective actions in order to save lives and property.
  • When a tornado warning has been issued by the National Weather Service (NWS) for Collin County naming McKinney in the path.
  • When a tornado has been sighted and confirmed in McKinney or is in close proximity to the city.
  • The first Saturday of each month at noon for testing, weather permitting.


The city has never utilized an all-clear as part of its warning process and will not sound the sirens to indicate an all-clear. If the city activates the Outdoor Warning System Sirens, move inside, take cover and monitor the situation via TV, radio or other means. By monitoring the situation, you can make informed decisions and know when it is safe to leave your designated safe room.