Monday June 17, Red Flag Warning. No Open Burning in Boulder County

Emergency Status
Apr 03

Emergency warning sirens to be tested beginning April 6

Boulder County, City of Boulder, Lafayette and Lyons will begin audible testing of the countywide emergency sirens at 10 a.m. on Monday, April 6.

The test is the first of the monthly emergency audible siren tests, which take place each year on the first Monday of each month from April through August. The audible siren tests will occur twice on each testing day, at 10 a.m. and 7 p.m., on April 6, May 4, June 1, July 6 and August 3.

Siren tests ensure that all systems and procedures are working properly during the season of peak flood danger and is in no way related to COVID-19. The tests also promote public awareness of the warning sirens located throughout Boulder County. Sirens are meant to reach people that are outside, not indoors.

Louisville, Superior, Erie and Jamestown will not participate in the first audible test on April 6.

The annual siren testing is a good reminder for community members to sign up for emergency alerts at This system allows all community members in Boulder County and all cities within the county to be notified of emergency situations in a variety of ways including on their cell phone, home and work phones and by text messaging and e-mail.

Should Boulder County experience severe weather during one of the planned audible tests, the siren tests for that day may be cancelled. For updated information, visit

Community members are encouraged to review their own emergency preparedness plans and discuss what they would do in the event of a flash flood or other emergency. For more information about personal preparedness, visit

Used to alert community members to potential danger from a flood or other immediate threat, there are 29 outdoor warning sirens in place across Boulder County, including in Boulder, Erie, Jamestown, Lafayette, Louisville, Lyons, Marshall, Eldorado Springs, Superior and the University of Colorado at Boulder.

All Boulder County sirens undergo weekly tests throughout the year, using a software program that performs a “silent” test.