Emergency Sirens
The outdoor warning siren system consists of 10 large outdoor warning sirens located throughout the City of North Richland Hills. These sirens are activated when there is an immediate danger from a tornado, national security threat or environmental hazard.

How to React
The sirens are designed to warn people who are outside to go inside and turn on their local television or radio stations to find out what the situation is.

Siren Types
There are two types of signals generated by these sirens: 

• Steady Tone - A steady tone indicates a threat from either a tornado or environmental hazard 
• Rise and Fall Siren - A rise and fall tone indicates public danger from a national security threat

Testing
The outdoor warning system is tested at 1:00 p.m. on the first Wednesday of each month. The sirens will not be tested if inclement weather is forecasted or is in the immediate area.