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March 29, 2024

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Outdoor warning sirens to be tested as part of annual flood season.

First Test Date is April 1

Boulder County, Colo. – The outdoor emergency sirens will be tested as part of annual flood season preparedness in communities around Boulder County.

The first audible test of the season will occur on April 1, 2024, in the communities of Boulder, Eldorado Springs, Erie, Jamestown, Lafayette, Louisville, Lyons, Marshall, and Superior. The test will occur twice on each testing day, at 10 a.m. and 7 p.m. on the first Monday of the month from April to August. After the first audible test in April, only the communities of Boulder and Lyons will perform the audible test, all other communities will conduct silent tests.

The outdoor emergency sirens warn community members about weather related emergencies, and depending on programming, hazardous materials and wildfires. Sirens are meant to reach and be heard by people that are outside, not indoors. Should Boulder County experience severe weather or a significant emergency incident occurring during one of the planned audible tests, the siren tests for that day may be canceled.

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 during the season of peak flood danger. The tests also promote public awareness of the warning sirens located throughout Boulder County during our flood season from April to August.

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 to be notified of emergency situations in a variety of ways including on their cell phone, home, work phones, text messaging, and email.

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, including upcoming training courses, please visit: