All-Hazards Outdoor Warning Siren System & Weather Message Polygon Warning System

This is one of Elmore County’s 63 Outdoor All Hazards Siren!


Warning Sirens Map PNG

 This is a map of the siren locations within Elmore County

All-Hazards Outdoor Warning Siren System & Weather Message Polygon Warning System: Outdoor warning sirens are pre-event warning devices. Sirens are designed to alert citizens who are outdoors of an imminent hazard and prompt them to seek shelter and additional information on the nature of the threat, including timing, location, and severity. Sirens are tested on the first Wednesday of each month, weather permitting.Although not required by law, they are important devices used to warn citizens of an imminent hazard. Most, but not all, of the populated areas in Elmore County are within the audible range of a siren—theoretically a radius of one mile, depending on factors such as distance from the horn, wind, hills, valleys, buildings, trees, other obstructions, and the ambient noise level around the listener. When sounded, sirens may not be an effective warning device for those persons in dwellings or automobiles.The county-wide outdoor warning system currently consists of sixty-three (63) all-hazards warning sirens installed and operating throughout Elmore County. Each siren includes:

  •  AC power with battery back-up system (applies to 22 of 63 sirens)
  • Radio-controlled activation
  • Automatic polygon activation by computer directly from the NWS by satellite and/or internet feeds (provided by Weather Message software, monitored by EMA)

Through the use of a commercial polygon warning system (Weather Message) in Elmore County, sirens have been grouped geographically into seven (7) separate zones. The National Weather Service (NWS) is the sole authority for issuance of warning notifications. Once the NWS issues a tornado warning, all sirens within each zone located within the designated polygon warning area will be activated automatically. Sirens in zones located outside the designated polygon warning area will not automatically activate, nor should they be activated manually by any PSAP unless given explicit direction to do so by the Elmore County Emergency Management Agency or the Chief Official of the PSAP.

  •  Activation Conditions

Activation of the all-hazards outdoor warning sirens is automatic and/or authorized (for manual activation) under the following conditions:

 Tornado Warning

  • Issued by the National Weather Service
  • Activation of sirens is automatic based on Elmore County’s utilization of a commercial polygon warning system (Weather Message)
  • If a tornado is spotted and the PSAP deems it as a credible source

   Civil Emergency Message (CEM)

  • Requested by local authorities, issued by the National Weather Service. Elmore County EMA is the single local coordinating authority between local officials and the NWS
  • Sirens (individual or by zone(s)) require manual activation
  • PSAPs must not activate sirens covering warned areas included in the CEM without receiving prior consent from Elmore County EMA or the Chief Official of the PSAP


  • Activation Duration

 When activated, the tone should be sounded for 3-5 minutes, re-sounding every 10-15 minutes for the duration of the threat (warning period).

  •  All Clear

 There will not be an all-clear signal from the outdoor warning sirens. People in or near the warned area should monitor reliable sources such as NOAA Weather Radio All- Hazards, local media, or EMA’s website at or .org to know when the hazard threat has dissipated.