Media Release: Random Outdoor Warning Siren Activations on February 16 at approximately 10:05 p.m.

Date: February 17, 2026

Rochester, Minn. - On February 16, 2026, at approximately 10:05 p.m., and for approximately 20 minutes thereafter, the Rochester/Olmsted County Emergency Communications Center (ECC - dispatch) began receiving calls of several Outdoor Warning Sirens sounding in northeast and southeast Rochester and as far east as Chester Woods Park. The ECC contacted the Olmsted County Emergency Operations Center (EOC) and EOC staff were able to shut down and reset the Outdoor Warning Siren system.

Olmsted County EOC staff immediately contacted Federal Signal’s authorized maintenance provider, Blue Valley Public Safety, to begin remedying the issue to ensure the likelihood of this happening again is mitigated.  A digital forensics assessment is underway to determine the cause of these random Outdoor Warning Siren activations. Preliminary evidence across Federal Signal enterprise logs shows no signs of infiltration and/or cyberattack. Blue Valley Public Safety worked with EOC staff to change the broadcast encryption key for its system and will take more intensive steps today, February 17, 2026, to ensure new encryption keys are encoded across all of Olmsted County’s Outdoor Warning Siren system.

Although random Outdoor Warning Siren activations are rare, they can and do occur. Two known circumstances that can cause random activations are the rebroadcasting of siren signal tones on the same radio frequency as a siren operates, and high-level solar activity, especially at night, can create conditions for skywave propagation. A rebroadcasting of siren signal tones must be completed close to the physical Outdoor Warning Siren site; meaning this would be human-caused, intentional, and extremely difficult to trace. High-level solar activity, which we are in those conditions currently, can cause radio signals to travel much farther than designed. If the same broadcast encryption key is being used by another jurisdiction, it could activate sirens from hundreds of miles away; also human-caused but not intentional, and often traceable.

Thankfully, other than the nuisance of noise late on a Monday night, no apparent damage has been done. Olmsted County EOC staff would like to thank our residents who called to report the activated Outdoor Warning Sirens in their neighborhoods.

For more information about Outdoor Warning Siren Systems, please visit the National Weather Service Outdoor Warning Siren Information webpage.