Outdoor Warning Sirens

Outdoor Warning Siren Information Sheet(PDF, 469KB)

Siren Map 2025(PDF, 9MB)

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FAQ

Q. Why use outdoor warning sirens?

A. Sirens are still the most effective method to warn the population at large in the shortest amount of time. People who may be outdoors at ball games, in their yard, or anywhere else where they are not in contact with the normal news media channels such as radio, TV or local public address systems, will get immediate notification of severe weather or any other emergency that requires taking shelter.

Q. How are they activated?

A. Radio control is the most popular method of activating sirens. To activate the siren system, the operator presses a button and a radio signal is transmitted. The signals are picked up by the receivers at the sirens. They decode the paging signals to determine what they are to do. A particular signal may instruct the sirens to give a weather warning call, while still another may cause the sirens to stop their sounding. With the new generation of communication signal processors, the variations are limitless.

Q. Why are they called outdoor warning sirens?

A. The sirens are called outdoor warning sirens because their primary purpose is to alert people who are outside to severe weather, chemical, or other emergencies. While you may be able to hear the siren in your house, this is not the primary function of the outdoor warning siren.

Q. Why can't I hear the siren in my basement?

A. Each siren is rated at 127 dB (decibels). The sirens are located in a grid system with approximately 1 mile separation.127 dB is slightly "louder" than a jet engine on take off. Comparing the sirens to the plane; the farther away the plane gets, the weaker the noise. In addition to distance, other factors effect how sound travels. Wind, terrain, other background noise (TV, stereo) and building walls reduce sound travel. The combination of building walls (insulation) and other interior background noise reduces the exterior noise you can hear inside your house. 140 dB can damage hearing, so there is a practical limit to how loud the outdoor warning sirens can be and still be effective. The 1 mile separation distance with the overlapping grid is considered to be one of the most effective methods to alert persons who are out of doors to seek shelter and tune in a local broadcast station to receive emergency information and instructions.

Q. Why aren't there more sirens?

Purchasing and placing of the sirens is dependent on several things, the primary one being the availability of funds to purchase and install them. The sirens have been purchased with special purpose tax funds that have been approved by the voters, and determining the locations and needs for new sirens is dependent on growth and development.

Q. When are the outdoor warning sirens tested?

A. The outdoor warning sirens are tested at noon on the first Friday of each month. In the event of threatening weather, the test may be postponed.

Q. What should I do if I hear an outdoor warning siren?

A. If you hear an outdoor warning siren you should seek shelter immediately. Once inside, you should turn on a local television station or radio station (KFBC AM 1240) to find out further information. Local officials will be disseminating information about the emergency through these outlets. An all hazards weather alert radio is a good tool to have in your home during any emergency situation.

Q. Why aren't the sirens sounding throughout the whole county anymore when there is an emergency?

A. The sirens will only be activated in the area of the County that the emergency is affecting. Laramie County is such a large County that it would be unnecessary to alert residents in the one part of the County about an emergency that will have no affect on their area.

 

If you have a question regarding the outdoor warning system please submit an e-mail to: LCEMA@laramiecountywy.gov

 

 

 

2026 Siren Expansion Project

The outdoor warning sirens for all of Laramie County including the City of Cheyenne are operated and maintained by the Cheyenne/Laramie County Emergency Management Agency (CLCEMA).  There are a total of 67 sirens in the system that are strategically spaced throughout the county to provide an alert when tornado warnings are issued.  Funds for the operation and maintenance of the system are provided through the 6th Penny ballot every few years.  

Activation of the sirens through our system works in conjunction with the tornado warning polygons that are issued by the National Weather Service (NWS).  Groups of sirens are placed in zoned areas that divide the county.  When an NWS tornado warning touches the boundaries of the affected zone, the sirens will automatically be activated.  In the event that this system malfunctions, CLCEMA and Laramie County Combined Communications Center (911 Dispatch) staff are able to access the system and activate them remotely.

The last time additional sirens were added to the county was in 2020.  Since then we continue to see additional growth throughout the area and thereby further identify the need for more outdoor warning sirens.  The costs associated with maintaining the system include the annual preventative maintenance for all sirens ($42,000/year) along with equipment and battery replacement ($12,000/year).  In today's market, a single new siren costs approximately $50,000. The 6th Penny ballot funds not only maintain our current sirens, but also allow us to add more as our population grows.  The community's continued support through the 6th Penny ballot has allowed us to ensure that our residents are kept safe during the tornado season.

For 2026, CLCEMA has started the Siren Expansion Project which will add 10 new sirens and replace the poles for 7 existing sirens which are warped.  The estimated cost of this project is approximately $520,000.  The locations have yet to be determined however information will be provided to those specific areas during the planning and to the Laramie County community when the planning is complete.  As the project progresses, we will provide updates on our website.

Sirens purchased with 6th Penny Specific Purpose Optional Tax Funds