Why is this project being considered?

There are 22 outdoor warning sirens in Ann Arbor.

From March to October, they are tested on the second Tuesday of the month with a one-minute wail. They are an outdoor warning system only. They are not intended to be heard indoors.

When sirens are activated, it may be for a variety of reasons, including a tornado warning, a severe thunderstorm warning with confirmed winds of 75 miles per hour or greater, or a hazardous material spill that requires immediate protective action.

They have been used twice in the past five years. Both instances were in July 2023: once to alert people to severe weather during the Ann Arbor Art Fair, and then, several days later, to alert people to severe thunderstorms with high winds.

The sirens are an attention-getting tool, not an information source. When activated, residents are instructed to “go in and tune in” to the radio, television, or other information sources for details.

Ann Arbor’s siren system is old and is in need of repairs and regular maintenance. The city expects to spend $60,000 each of the next three years on repairs, then roughly $17,000 annually on maintenance.

There are now ways to reach people with clearer warning information, including through their cell phones.

Work that may be done

If the sirens are decommissioned, Ann Arbor would continue to warn residents in multiple ways.

Decommissioning the sirens would not eliminate warnings — it would shift them to more effective channels. The city will expand public education on how to receive and respond to alerts.

These tools provide clear instructions, language accessibility, and geographic precision that outdoor sirens cannot:

• Wireless Emergency Alerts – These alerts are automatically delivered to all WEA-capable cell phones in a defined geographic area. No sign-up is required (WEAs are opt-out only). They are used for imminent, life-threatening emergencies (e.g., tornado warnings, severe thunderstorm warnings, hazardous material spills) and are issued by the National Weather Service and Washtenaw County Sheriff’s Office. They provide clear, written instructions with distinctive tones and vibrations.
• A2 Emergency Alerts – Ann Arbor’s opt-in system for informational and lower-threat alerts. They are delivered by text, email, or phone call and can be targeted geographically within the city.

Potential cost to system retirement

If Ann Arbor chooses to retire the warning siren system, there will be a cost to remove the sirens. The city will obtain a cost estimate if retirement is determined to be the best path forward for the community.

The proposed decommissioning is based on three core principles:

1. Public safety effectiveness – Modern alerting tools better reach residents where they are, especially indoors.
2. Clarity and comprehension – Alerts that explain the threat and required action reduce confusion and boost the number of people who act accordingly.
3. Responsible use of public funds – Redirecting resources from aging infrastructure toward education and modern systems maximizes safety impact.

Decommissioning sirens does not mean reducing emergency warning capability. Instead, it reflects a shift toward systems that align with how people receive information today.

Throughout March 2026, the city will solicit feedback from residents on the possible decommissioning of warning sirens.