The outdoor warning sirens are sounded only in the event of an emergency or during pre-announced tests. The sirens are activated through the Boulder County Sheriff's Communications, Boulder Police and Fire Communications, and Longmont Police and Fire Communication centers.
When you hear a siren, you should:
- 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