University of California, Berkeley
Office of Emergency Preparedness
Office of Emergency Preparedness
About Us Emergencies Programs Services Resources Campus Disaster Response Alerting & Warning System Emergency Contacts


Location 1 Sproul Hall
Room 17
CA 94720-1199
Alerting & Warning System

What is the Alerting and Warning System?

The Alerting and Warning System (AWS) is a network of safety sirens and communications links that warn and inform the community of what to do in an emergency or disaster. Local systems are operational in the Cities of San Leandro, Alameda and Oakland, with additional Alameda County cities to join in the coming months and years. The University of California, Berkeley currently has sirens covering the main campus in the heart of the city.

The AWS, a critical element of the campus emergency preparedness program, was developed to save lives and minimize property damage during an emergency. The hazard warning sirens and communications links will work in tandem to alert, warn and provide specific emergency information to citizens in the event of certain emergencies. This includes dangers resulting from natural or technical hazards such as chemical spills, flooding, fires, storms, power outages, transportation incidents, and other public safety incidents. Upon hearing a siren, community members should immediately Shelter-Shut-Listen, then use the communications links to quickly obtain emergency information, such as disaster type, evacuation routes, shelter and aid locations, special instructions, etc. Community members should remain in the Shelter-Shut-Listen mode until further notification from the university.

Shelter-Shut-Listen   Siren System Locations

• UC Berkeley Alerting & Warning System "Shelter - Shut - Listen" flyer. Shelter Shut Listen Flyer (28Kb)


• UC Berkeley Alerting & Warning Siren System Location.AWS Siren Map of Campus (544Kb)


Alerting & Warning System Elements

Sirens / Public Address System
The four hazard warning sirens are strategically located across the campus to cover the main campus and adjacent campus facilities.  The University of California Police Department activates these sirens.  Depending on the incident, either or both sirens and public address announcements may be transmitted over this system.  Upon hearing a siren, or in any campus-wide emergency, individuals should access one of the following sites to acquire information relating to the situation:

The proactive notification system. Affiliated community members (faculty, staff, and students) must visit and submit their contact information. In the event of an emergency, officials at UC Berkeley will use the system to broadcast a message to those registered users, reaching them directly at the phone numbers or email addresses they have specified. For more information about WarnMe, and to add your contact information to the system, visit

Out-of-Area 800 Service Emergency Information Line:      1-800–705-9998
This toll-free number allows recorded messages to be accessed by any standard, cell or pay phone, free of toll charges. Publice Affairs, working in conjunction with the Police Department, updates this message as the situation evolves.

Web site:
The off-site alternate emergency Web presence is reachable anytime, from anywhere.   Like the 800 service, this web-site would not impacted by local area power failures or other crisis conditions.

Radio Station: KALX 90.7 FM
The campus radio station, broadcasting at 500 watts, will be utilized to disseminate emergency information during critical incidents and disasters.


Alerting & Warning System FAQ's

Q: What is the “Alerting and Warning System”?
A: The “Alerting and Warning System” (AWS) is a network of warning sirens and media links that warn and inform the campus community in the event of certain emergencies. This includes dangers resulting from natural or technical hazards like earthquakes, chemical spills, flooding, power outages, transportation incidents, and other public safety incidents.

Q: When does the system conduct its test?
A: Sirens are tested on the first Wednesday of each month at noon.

Q: What does it mean when I hear a siren?
A: A siren alert on a non-testing day means that there is an emergency in your area, a potentially dangerous condition, or impending threat.

Q: What should I do if I hear the warning siren on campus?
A: Shelter - go inside
Shut - shut the doors and windows
Listen - do one of the following three things:
call the emergency hotline at 1-800-705-9998
log on to the campus emergency web page
listen to the campus radio station: KALX, 90.7 FM. Wait for instructions, then follow them.

Q: When will this system be used?
A: This alerting and warning system might be used for a number of emergency situations. These would include alerting of danger resulting from natural or technical hazards such as chemical spills, flooding, wildfire, storms, power outages, transportation incidents, and other public safety incidents.

Q: When I hear the siren, how will I know what kind of emergency is happening?
A: The siren itself will not indicate the type of emergency, but will let you know there is an emergency. For information about the emergency and what action to take, you must “Shelter, Shut and Listen”. (See above). WarnMe, the campus emergency notification system, can indicate the type of emergency in its messages. Sign up for that at

Q: Do we go home when we hear the siren?
A: No. Remember: “Shelter, Shut, and Listen”. If an evacuation needs to occur, that information will be given through the emergency hotline at 1-800-705-9998, the campus emergency web page, and the campus radio station: KALX, 90.7 FM.

Q: Will I be able to hear the siren if I am inside a building?
A: There will be certain locations in the interior parts and basements of campus buildings where the siren is not audible. It will be important for those who do hear it to notify those who may not. Spread the word!

Q: If I am driving, will I hear the siren?
A: It will depend on how close you are to the siren, whether you have the radio on, and whether your car windows are open. You may or may not hear the siren.

Q: What is the sound range of the campus warning siren?
A: The siren sound range is approximately ½ mile. The sound range will vary based on location and conditions, such as hill terrain, tall buildings, or high outdoor noise levels. On campus, sirens are placed so that they overlap each other, to provide better sound coverage. (See map Shelter Shut Listen Map (544Kb) .)

Q: How does the siren system operate?
A: The sirens, which are located on top of Wurster, Tolman, Evans, and Eshelman Halls, will be activated from the campus Police Dispatch Communications Center. The siren system will be radio-operated using the campus 800-megahertz radio system. It is computer-controlled, using digital technology with a manual system back-up. During an emergency, all four siren(s) may be activated or only sirens in a particular area. UCPD’s Office of Emergency Preparedness also has the capability to operate the system.

Q: We work in a building that is off-campus. How does this affect us?
A: This alerting and warning system can only be heard on the Central Campus and immediately surrounding areas. It is unlikely for the siren to reach the Hill Area, Clark Kerr Campus, Albany Village, or buildings further than 3 or 4 blocks from the main campus.

Q: How will we know the difference between a test and an actual emergency on days scheduled for testing?
A: Any activation of the siren at a time and date other than the first Wednesday of each month at noon should be considered a real activation. A voice announcement will precede the siren on test days, reminding people that the following siren sound is only a test.

Q: Do I need to do anything during the tests?
A: If you hear the siren on a test day (first Wednesday of the month), you do not need to do anything. The system is simply being tested for functionality.

Q: Who else is using the Alerting and Warning System?
A: Local systems are becoming operational in the Cities of San Leandro, Oakland, and Alameda, with additional Alameda County cities to join in the coming months and years. Contra Costa County has used a version of this system for a number of years. UC Berkeley has used it since February 5, 2003.

Q: What should I do if I hear a warning siren in another East Bay location?
A: The same as above: Shelter, Shut, and Listen (turn on the radio; tune to a local emergency broadcast news station like KGO, KCBS or KNBR; or your city’s emergency broadcast station, and listen for instructions.)

Q: Do all East Bay warning sirens conduct tests at the same time?
A: No. Contra Costa County conducts tests of their warning sirens on the first Wednesday of the month, but at 11am. Occasionally, weather conditions allow the sound of those sirens to be heard in Berkeley. Siren tests in Contra Costa County last only 90 seconds. Actual emergency sirens will sound for three minutes. More info about Contra Costa County's Emergency Warning System. If you suspect that the siren system you hear is not from the Berkeley campus, you can check this website to confirm a test. Governor's Office of Emergency Services


Q: Will WarnMe messages reach all students and staff?
A: In a test soon after launch of the system, 67.5% of the targeted test group acknowledged receipt of the message. Read more in this NewsCenter article.



UC Seal
OEP Home Site Map Feedback Contact Webmaster Contact Us
©20062012 University of California, Berkeley; Office of Emergency Preparedness. All rights reserved.