Receiving Emergency Alerts

Joliet has outdoor warning sirens placed in strategic locations throughout the city. Although the warning sirens can sometimes be heard indoors, they are meant for outdoor warnings only.

For indoor warnings, use a NOAA Weather Radio, a Wireless Emergency Alert-capable cell phone, and TV or internet sources. No device is perfect, so having multiple ways of receiving alerts is a must.

Tornado Watch Versus Tornado Warning

Tornado Watch: This means conditions are favorable for severe thunderstorms and tornadoes to develop in the watch area. The watch area generally includes many counties (several thousand square miles) and lasts for several hours.

Tornado Warning: This means a tornado is occurring or imminent. The warned area is much smaller and only covers the immediate area affected by the storm.

Outdoor Warning Siren Activation Policy

The City of Joliet will activate the Outdoor Warning Sirens for the following criteria:

  1. The City of Joliet is under a Tornado Warning issued by the National Weather Service.
  2. Any part of the City of Joliet is within a Tornado Warning Polygon issued by the National Weather Service.
  3. Sustained Winds greater than 65 MPH are being experienced.
  • Tornado Warning: A tornado has been reported or is highly likely to occur based on Doppler radar signatures.
  • Polygon: A specific location most likely to be affected by severe weather.
  • 65MPH: This wind speed is on the lower side of an EF-0 tornado.