MINNEAPOLIMEDIA NEWS | Hennepin County Upgrades Outdoor Warning Siren System as Neighborhood Testing Continues

HENNEPIN COUNTY, MN (July 14, 2026)  Hennepin County is undertaking a multi-month upgrade of Minnesota’s largest coordinated outdoor warning-siren system, a project that will occasionally produce short siren sounds in neighborhoods while technicians test the new equipment.

The existing siren-control system will remain operational until the replacement has been installed, tested and determined to be fully functional.

That overlap is intended to preserve emergency-warning coverage throughout the transition.

Residents May Hear Short “Growl Tests”

As technicians move between siren locations, residents may hear brief sounds known as growl tests. These tests generally last 10 to 15 seconds and allow crews to verify the operation of individual sirens.

After installation, each siren may also be sounded twice for approximately 15 to 30 seconds during site-acceptance testing. The sounds include the time needed for the siren to spin up and slow down.

These neighborhood tests may occur outside the county’s customary monthly drill.

Monthly Testing Will Continue

Hennepin County’s regular siren test is scheduled for 1 p.m. on the first Wednesday of each month. During the system transition, the old and new systems will be tested within the same period.

Some residents may notice minor delays or differences in the timing of sirens during monthly drills. County officials said those variations are expected while technicians coordinate the two systems and do not necessarily indicate a malfunction.

Testing may be delayed or canceled when severe weather threatens. Officials avoid routine siren tests during potentially dangerous conditions because residents must be able to distinguish a drill from a genuine warning.

Sirens Are Designed to Warn People Outdoors

Outdoor warning sirens are primarily intended to alert people who are outside. They may not be loud enough to awaken someone inside a home or be heard over air conditioners, televisions or other indoor noise.

Residents should not depend on sirens as their only source of emergency information.

Households are encouraged to maintain multiple warning methods, including:

• Wireless emergency alerts on mobile phones
• Local television and radio broadcasts
• Weather applications with alerts enabled
• A NOAA Weather Radio

When a siren sounds outside a scheduled test, residents should move indoors immediately and seek additional information. A siren is a signal to take shelter and find out what is happening, not an all-clear notification.

What Residents Should Expect

The transition will continue for several months. Brief neighborhood tests may occur as work progresses across Hennepin County, but residents should hear little difference during ordinary monthly drills.

Anyone concerned about a siren test should check official city or county communications before calling emergency dispatch. However, if threatening weather is present or there is uncertainty about whether the sound is a test, residents should take shelter first.

Source: Hennepin County siren-upgrade information.

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