Warning Systems

Outdoor Warning Sirens

The siren system is an all-hazard warning system used to alert citizens who are outdoors to potential danger. More than thirty outdoor warning sirens are in place across Boulder County.

The same signal is used whether the emergency is a flood, tornado or other disaster. If you hear a siren, tune to a local TV or radio station for further information.

The outdoor warning sirens are sounded only in the event of an emergency or during preannounced tests. The sirens are tested April-September on the first Monday of each month at 10:00 am and 7:00 pm.

ACTUAL EMERGENCIES - sirens sound for five minutes
TESTS - sirens sound for two minutes

If you hear a siren

  • Visit www.boulderoem.com for the latest emergency information.
  • Tune-in to radio stations KOA 850 am, KBCO 1190 am or 97.3 FM.
  • Turn-on local television news channels (2, 4, 7, 9 or 31) Listen for a voice message if you are near a voice activated siren.
  • Refrain from calling 911 unless you are experiencing an emergency.

Sign up for EMERGENCY ALERT NOTIFICATIONS today at www.boco911alert.com

The Emergency Notification System (ENS)

The ENS is used to call landline and cellular phones, send text messages and send emails, to inform the public of immediate threats to health and safety. Examples include the need to evacuate during a wildfire, take appropriate action during a flashflood, or stay inside because of critical police activity in your area.

  1. A brief message is recorded by the agency that answers 911 calls in your area.
  2. The system allows the agency to select who is called by defining an area on a map or by inputting a range of addresses.
  3. The message is then 'launched.' The system automatically calls each landline number in the selected area, playing the recorded message when the phone is answered.
  4. The system also calls other phone numbers, sends text messages, and sends emails to residents who have "opted in" to the system for additional notification.
  5. To sign up for emergency alert messages, go to www.boco911alert.com
  6. If the phone is busy, the system will re-try. If an answering machine is encountered, the system will attempt to leave a message.
  7. If a TDD signal is encountered, the system will leave a TDD message.
  8. When you receive an emergency alert call, listen carefully to the information in the recorded message. It will contain: a) The name of the agency that recorded the message.
    b) Details as to the nature of the impending danger.
    c) What action you need to take.
  9. You may repeat the message by following the system prompts. Do not hang up in the middle of the message; the entire message must be left for the system to show it was received.
  10. If you have signed up to be notified in multiple ways (work phone, cell phone, and text message, for example) the system will stop trying to reach you once you acknowledge that you have received the message in one of these ways.

Emergency Alert System (EAS)

Formally called the Emergency Broadcast System, EAS transmits national, state and local emergency warning information over television and radio stations. It automatically interrupts regular programming to provide information for your specific viewing area.

NOAA Weather Radio (NWR) All Hazards

NWR is a nationwide network of radio stations that broadcast continuous weather information directly from the nearest National Weather Service (NWS) office. NWR broadcasts official Weather Service warnings, watches, forecasts and other hazard information 24 hours a day, 7 days a week.

NWR also works with the FCC's Emergency Alert System (EAS) to be an "all-hazards" radio network, making it a single source for emergency information. In conjunction with Federal, State and local public safety officials and emergency managers, NWR can broadcast warning and post-event information about all types of hazards – natural (such as winter storms or flash flood), environmental (such as a chemical spill), or public safety (such as an AMBER alert).

Here's how it works. During an emergency, NWS sends a special tone that activates the weather radio in the affected area. When the weather radio is activated, an alarm tone sounds and then you will hear specific information about the potential or imminent hazard. NOAA

Weather radios are available at many retail outlets, including electronics, department, and sporting goods stores, as well as many grocery stores. They can also be purchased via the Internet from online retailers or directly from manufacturers. They are available with many different features, and can cost anywhere from $20 to $200. A few of the more useful features include:

  • Tone alarm: The alarm tone will activate for watch and warning messages even if the receiver is turned off.
  • S.A.M.E. technology: Specific Alert Message Encoding allows you to specify the area for which you would like to receive alerts. Without this feature, you may hear watches and warnings for several counties. With this feature, you will hear messages only about the areas you have selected.
  • Battery backup: This feature is useful since power outages often accompany severe weather. It is recommended that you use the AC power under normal conditions, however, in order to preserve battery life. For more information, and to program your weather radio, go to http://www.weather.gov/nwr/.