In Erie, the Outdoor Warning Sirens are tested audibly on the first Monday of April.
All Boulder County sirens undergo weekly tests throughout the year using a software program that performs a “silent” test. All communities have been using the silent test system for years with a high degree of reliability. Audible testing is an additional way to check if sirens are working properly.
For testing details, visit the agency that facilitates testing, the Boulder Office of Disaster Management.