Early Warning
Learn how California’s Earthquake Early Warning system works, how to get alerts through MyShake and WEA, and access official tools and information.
Get alerts before shaking starts
Earthquake Warning California is the nation’s first statewide system that can give you crucial seconds of warning before you feel shaking.
Managed by the California Governor’s Office of Emergency Services, the system uses ground motion sensors across the state to detect earthquakes in real time and notify people to Drop, Cover, and Hold On.
Alerts are delivered through the MyShake app, supported mobile operating systems, and Wireless Emergency Alerts (WEA).
Detailed information about how the system works, how to receive alerts, and available tools is provided on the official state website.