National Weather Service United States Department of Commerce



In July 2009, Common guidelines for activating outdoor warning sirens were formally adopted by Rock Island County, Scott County, Rock Island Arsenal as well as the cities of Moline, East Moline, Rock Island, Davenport, Bettendorf and many smaller communities.

Under the Quad City Metro area outdoor warning system guidelines, outdoor warning sirens will be sounded for:

  • tornadoes
  • thunderstorms with winds 70 mph or greater (potential for whole trees to snap or uproot)
  • golf ball sized hail or larger (potential for windows to break)

Frequently Asked Questions

Helpful Documents:

Siren Guidelines One-pager

Complete Siren Guidelines 



1.  What do the guidelines say?  
Under the Quad City Metro area outdoor warning system guidelines, sirens will be sounded for:
  • Tornadoes,
  • Thunderstorms with winds 70 mph or greater (potential for whole trees to snap or uproot)
  • Golf ball sized hail or larger (potential for windows to break)
The same tone will be used for all threats in each community, and the sirens may be sounded multiple times during the threat. There will be no all-clear signal from sirens.
2.  What should I do when I hear outdoor warning sirens?
When the sirens are heard, go inside and tune to local media to get more information. 
3.  When are outdoor warning sirens tested?
Sirens will be tested simultaneously on the first Tuesday of each month. (This will be a change for some communities in the Quad City area.)
4.  Why don’t the outdoor warning sirens sound an all-clear signal?
People should be indoors and monitoring local media for updates on the storm. 
5.  Why will the outdoor warning sirens be sounded for hail and wind?
When thunderstorm winds exceed 70 mph, trees can be uprooted or snapped. Hail that is golf ball sized or larger can break windows. Both of these things pose a direct risk to life if people are caught outdoors. 
6.  How often can I expect the outdoor warning sirens to sound for severe weather?
On average, the Quad City area experiences 5 storms each year that meet the siren guidelines. 
7.  Why were the guidelines developed?
When life-threatening weather is approaching, minutes or even seconds could make a difference. If people are unsure or confused about an alert, they may not respond quickly or appropriately. By adopting common outdoor warning system guidelines, confusion will be eliminated, response time will be reduced, and lives will be saved.
8.  How were the guidelines developed?
Emergency management officials from Scott County, Rock Island County, and the Rock Island Arsenal developed the guidelines together in cooperation with the National Weather Service. Input on the draft guidelines was also sought from dispatch centers across the metro area. During the spring of 2009, the final guideline recommendation was then shared with community governments. 
9.  Has my community adopted the guidelines?
Support across the metro area for a unified outdoor warning system policy has been extremely strong. Within a few months of distribution, the guidelines were formally adopted by the Rock Island Arsenal, Rock Island County, and Scott County, as well as the cities of Moline, East Moline, Rock Island, Davenport, and Bettendorf. Many smaller communities in the Quad Cities commuting area have also adopted the guidelines. Check with your local city council if you have questions about whether your town has adopted the guidelines.
10.  Why can’t I hear the outdoor warning sirens in my house?
Sirens are an outdoor warning system designed only to alert those who are outside that something dangerous is approaching. 
11.  How can I get alerts when I’m at work or in my house?
For alerts indoors, every home and business should have a NOAA Weather Radio All-Hazards. NOAA Weather Radio is like a smoke detector for severe weather, and it can wake you up when a warning is issued for your area so you can take appropriate action.
12.  Will the outdoor warning sirens warn me of every dangerous storm?
The safest approach is to be proactive and use all of the information available to protect yourself and your family from threatening weather. Nothing can replace common sense. If a storm is approaching, the lightning alone is a threat. Sirens are only one part of a warning system that includes preparation, NOAA Weather Radio, and local media.
13.  Where can I read the guidelines?
The complete outdoor warning siren guideline document can be read here.
14.  Who activates the outdoor warning sirens?
Sirens are typically activated by city or county officials, usually a police or fire department or emergency management personnel.  Check with your city or county officials to learn more.
15.  Where can I get more information?