When a tornado watch or warning is issued, outdoor sirens across Milwaukee County signal the potential danger.
At least one tornado touched down in northwestern Wisconsin as severe thunderstorms moved across the state during the evening of Monday, April 13. A tornado warning issued for Milwaukee, Ozaukee and Washington counties expired overnight as storms moved out of the area.
With more severe weather in the forecast, here’s what to know about outdoor sirens in Milwaukee.
How often does Milwaukee County test outdoor sirens?
The Milwaukee County Office of Emergency Management tests its outdoor sirens at noon on the second Wednesday of each month, weather permitting, according to its website. The most recent test took place Wednesday, April 8.
The agency will also participate in statewide tornado drills scheduled for 1:45 p.m. and 6:45 p.m. April 16, when “schools, businesses, and families are encouraged to practice going to their nearest tornado shelter or safe location,” according to Wisconsin Emergency Management. If there is a possibility of severe weather on Wednesday, the statewide drills will be delayed until Friday, April 17.
What does it mean when outdoor warning sirens are activated?
In Milwaukee County, the outdoor warning sirens sound when there is a “tornado watch or warning,” according to the emergency management office.
The outdoor sirens are meant to be heard outside and people indoors shouldn’t count on hearing them in the event of severe weather, the agency said.
FOX6 Milwaukee Chief Meteorologist Tom Wachs said in a social media post that the decision of when to sound the sirens is up to individual county emergency management offices, though typically they’re activated when a tornado warning is issued.
“If you hear them, seek more info is what we usually say,” he said.
How many tornadoes are there in Wisconsin every year?
Wisconsin averages 23 tornadoes a year, according to Wisconsin Emergency Management. In 2025, the National Weather Service confirmed 39 tornadoes in the state.
How to stay safe during a tornado
When a tornado occurs, The National Weather Service recommends:
It is not safe to seek refuge in a vehicle or under an overpass. If you’re outside during a tornado warning, the safest option is to drive to a shelter, basement or safe room.
This article originally appeared on Milwaukee Journal Sentinel: When does Milwaukee County use its outdoor weather warning sirens?
Reporting by Chris Mueller, Milwaukee Journal Sentinel / Milwaukee Journal Sentinel
USA TODAY Network via Reuters Connect
