Severe weather season: What do the sirens mean?

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

As storm season arrives, you may occasionally hear warning sirens alerting you to severe weather, but what do the sirens mean?

According to the Quad City Metro area outdoor warning system guidelines, sirens go off for tornadoes, thunderstorms accompanied by winds of 70 mph or higher, or hail that is golf ball sized or larger.

All alerts will be sounded by city or county officials when they receive word that severe weather is approaching. No matter the kind of weather, sirens will sound with the same tone in each community. Sirens may be sounded multiple times for the same severe weather threats. There is no all-clear signal from sirens.

If you hear a siren, the best reaction is to go indoors and tune in to local media for information.

You may not be able to hear a siren if you are indoors. The sirens are designed to alert people who are outside that something dangerous is approaching.

For most Illinois communities, sirens are tested on the first Tuesday of every month at 10 a.m. Should a severe weather watch or warning be issued to a community before 10 a.m. on a testing day, the sirens will not be tested and regular testing will resume on the next scheduled monthly date. Iowa does not have a law regulating siren testing.

Activation guidelines and other information is available at the National Weather Service Quad Cities website.