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Emergency Management

Phone: 913-782-3038

111 S. Cherry St., Suite 100, Olathe, KS 66061

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Outdoor Siren Test

Why buy a NOAA Weather radio?

Johnson County’s outdoor warning system consists of 190 sirens placed strategically throughout the county as an early warning device to alert citizens of potential danger. While the outdoor warning system is an effective method of notifying those outdoors, it is only one component of a comprehensive emergency warning system including the use of the use of NOAA weather radios, the Emergency Alert System, and emergency notifications from local media. Through the Project Community Alert program these radios are available through local Price Choppers. Click here to find the one closest to your home.

Designed as an outdoor warning system, the sirens should not be relied upon to provide sufficient warning indoors or in noisy areas. Air-conditioning, thunder, wind, rain, and other conditions can cause the sirens not to be heard indoors or outdoors (even if sirens can be heard during tests). Sirens are also subject to lightning strikes and other equipment malfunction. Furthermore, sirens provide no information on the type of threat or exact location of potential danger. For this reason, if you hear the sirens, you should seek shelter immediately as the threat may be in your immediate area.

Individuals, families, and businesses are strongly encouraged to use NOAA weather radios to receive warnings and emergency information. Through Project Community Alert, an initiative of the Metropolitan Emergency Managers Committee, these radios are being sold at $29.95, a considerable savings over the regular price, at metro area Price Chopper stores. Additional information on this initiative can be found here.

To view the siren information in the AIMS Online Mapping System or click here.


The outdoor warning system for Johnson County is tested at 11:00am on the first Wednesday of the month. No tests are conducted when extreme cold and/or heavy icing might damage the equipment. Tests are also cancelled whenever there is severe weather (or potential severe weather) occurring in the local area and activating the outdoor warning system might cause confusion as to whether the activation is real event. If the monthly test is cancelled, it will typically be postponed one week to the second Wednesday of the month at 11 AM. If the rescheduled test is also cancelled, no additional testing will be performed that month.

In March, the sirens are also sounded as part of the statewide tornado drill in conjunction with the National Weather Service and the State of Kansas for Severe Weather Awareness Week. These drills are typically conducted on a Tuesday or Thursday (back-up date) afternoon, late enough as not to disrupt the school lunch period.


The cities within the county own and maintain the sirens within their cities. Johnson County Emergency Management has the primary responsibility to activate the sirens throughout the county. In addition, the cities of Lenexa, Olathe, and Overland Park have the capability of activating their own sirens if they so chose.

 There are three basic criteria to activate the sirens for tornadoes:

  • The National Weather Service issues a Tornado Warning for Johnson County,
  • A county trained and certified weather spotter reports a tornado; or
  • A tornado is reported by a local public safety official.

Johnson County has the capability of activating all of the sirens at once or by activating one or more of five established siren zones. All sirens are sounded unless the threat is clearly confined to an individual zone (or zones). During a tornado warning the sirens will be sounded for a three minute duration in ten minute intervals (three minutes on, seven minutes off) for as long as the tornado warning is in effect. There is NO “all-clear” siren.