San Francisco’s Outdoor Warning System sirens will go silent during upgrades

It’s a familiar sound in San Francisco; every Tuesday at noon, you can count on the city’s Outdoor Public Warning System siren to blare in a neighborhood near you. On December 10, the system of 119 sirens will go off for the last time— at least temporarily. 

The San Francisco Department of Emergency Management (SF DEM) announced on Tuesday, that the sirens, which each emit a loud 15-second tone as part of their weekly test will go silent. 

SF DEM says the antiquated sirens that have stood guard since World War II, are in need of an upgrade. The projected timeline is two years at an estimated budget of up to $2,500,000. 

The upgrades include a new operating system, stronger encryption and hardware to improve the reliability and security of the sirens.  

 The last upgrades to the system were made back in 2005.

So how will you know if there is a real emergency event, like a natural disaster, major police event, fire, or even things like tsunamis and radiological attacks? 
City officials are encouraging residents to sign up for AlertSF, the city’s emergency text message system. Simply text your zip code to 888-777 or visit to register. 

There’s also the tried and true Emergency Alert System (EAS) that you’ve likely seen interrupting television and radio broadcasts. Officials note in the event of a power outage, or if cell reception is offline, law enforcement officers, firefighters or other emergency personnel will be deployed to affected areas. 
The last time the sirens went off for a real-event emergency was in 2012 when there was potentially contaminated water on Treasure Island during a water-main break. 

For more information on the temporary alert system shutdown, click here