Sacramento, California – Sacramento is adding a new sound to its emergency safety toolbox, and city officials want residents to know exactly what it means before the next major disaster strikes.
The Sacramento Police Department is equipping newly built patrol vehicles with a Hi-Lo warning sound, a distinct alarm meant for one purpose only: large-scale evacuation warnings during major emergencies. The sound is not the same as a regular police siren. It is designed to stand out, cut through confusion and tell people nearby that they may need to leave immediately. (X (formerly Twitter))
Police say the Hi-Lo warning will be used only when everyone within hearing range is meant to receive the alert. That detail matters. Officers do not plan to use it during routine calls, traffic stops or standard emergency responses. Instead, it is reserved for serious public safety threats, including wildfires, dam failures, levee breaches and major flooding events.
The goal is simple, but important: make sure evacuation warnings can still reach people when other systems break down.
Sacramento residents already have several ways to receive emergency alerts, including cell phone notifications, radio messages, internet updates and other public warning tools. But disasters can be messy. Heavy smoke can limit visibility. Power outages can silence devices. Damaged towers or overloaded networks can delay messages. In those moments, a patrol vehicle moving through a neighborhood with a clear evacuation tone could become a critical backup.
Police are stressing that the Hi-Lo sound does not replace existing alert systems. It adds another layer. In a fast-moving emergency, that extra layer could help reach people who missed a text, lost power, had no internet access or could not receive a warning through normal channels.
Officials also want to avoid panic or confusion. That is why the sound will be used only in major evacuation situations, not casually and not as a general warning. When residents hear it, they should treat it as a signal to look for immediate evacuation information, follow instructions from emergency personnel and leave the area if directed.
The Sacramento Police Department is encouraging the public to become familiar with the sound ahead of time. Residents can visit the department’s YouTube page or listen to a Sacramento County Hi-Lo evacuation siren example online.
The message behind the new warning is direct: if the Hi-Lo sound comes through your neighborhood during a major emergency, it is not background noise. It is a call to act.