If you haven’t yet heard one of the county’s 131 sirens growl, you may during the next couple months. Weekdays through July, Pacific Gas & Electric, in coordination with the County of San Luis Obispo will be conducting annual maintenance on the Early Warning System sirens.

During the annual maintenance, each of the 131 sirens will be inspected and tested individually to help ensure the system is ready should it be needed during an emergency.

Following inspection, each siren will undergo a brief growl test. This short low volume test will last for a period of a few seconds. Although the public in close vicinity to the siren may hear a brief siren sound, no action is required on the part of the public.

The annual siren maintenance will be conducted weekdays from 8 a.m. to 4 p.m. and will continue through July.


For the month of April, crews will be working on sirens in the See Canyon area, followed by Arroyo Grande and Oceano. Should you hear a siren continue to sound, you should tune to a local radio or television station for emergency information. During an emergency, the sirens will be sounded for three minutes.

The sounding of the Early Warning System sirens is an indication that the Emergency Alert System has been activated and the public should tune to a local radio or television station for emergency information and instructions.

Although the Early Warning System sirens were installed and are maintained as one of the requirements related to the operation of the Diablo Canyon Power Plant, the sirens can be used for any local emergency where there is a need for the public to take action.

Additional information on the siren system as well as emergency preparedness information can be found at https://www.prepareslo.org.

Questions regarding the tests can be answered by the County Office of Emergency Services by calling (805) 781-5011.