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Emergency Management

Phone: 913-782-3038

111 S Cherry, 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.

To view a historic record of when and why the outdoor warning sirens have sounded in the past, click here.

What to do

If the outdoor warning system is heard at anytime other than scheduled test days, seek shelter and tune in to local radio, television, or your NOAA weather radio for instructions and information.

It is important to remember that any thunderstorm can produce a tornado with little or no warning. When a tornado warning is issued, take the following immediate safety precautions:

In homes or small buildings: Go to a pre-designated safe area such as the basement (if available) or to an interior room on the lowest floor, such as a closet or bathroom away from windows, doors, and outside walls. Upper floors are unsafe. If there is no time to descend, go to a closet, a small room with strong walls, or an inside hallway. Put as many walls as possible between you and the outside. Get under a sturdy protection (heavy table or work bench), cover yourself with some sort of thick padding (mattress, blankets, etc.), and use your arms to cover your head and neck to protect against flying debris.

In schools, hospitals, factories, or shopping centers: Go to interior rooms and halls on the lowest floor. Stay away from glass enclosed places or areas with wide-span roofs such as auditoriums and warehouses. Crouch down and cover your head and neck. Centrally-located stairwells are good shelter.

In high-rise buildings: Go to interior small rooms or halls. Stay away from exterior walls or glassy areas.

In cars: IF POSSIBLE, DRIVE AWAY! If not, get into a sturdy shelter (building). As a last resort, you need to make a personal decision whether to ride it out in your car hunched down below the windows with your SEATBELT ON, or to lie flat in the nearest ditch or depression with your hands covering your head. Be alert for flash floods. It is not recommended to seek shelter under overpasses.

In mobile homes: ABANDON THEM IMMEDIATELY! Most deaths occur in cars and mobile homes. If you are in a mobile home, leave it and go to a sturdy building providing greater protection. If your mobile home community has a designated shelter, make it your safe place.

If no suitable structure is nearby: Lie flat in the nearest ditch or depression and use your hands to cover your head. Be alert for flash floods. It is not recommended to seek shelter under overpasses.

Listen to a battery-powered NOAA weather radio or local radio or television station for updated information and to determine when conditions are safe.

Questions? Contact Terry Kegin, Assistant Director of Operations.