What Storm Sirens In Collin County Actually Mean

When outdoor warning sirens sound across North Texas, many assume it means a tornado is nearby. But despite the association, these sirens aren’t reserved for tornadoes alone.

On the evening of June 8, 2025, powerful storms swept through North Texas, bringing wind gusts of up to 65 miles per hour. Collin County cities, including Allen, Frisco, McKinney and more, activated their storm sirens to alert residents and ensure public safety.

Emergency management officials across the region emphasize that outdoor warning sirens are designed to alert people who are outside to seek more information and take shelter. Sirens may be activated for a range of hazards, including large hail, extreme wind or hazardous material incidents, not just funnel clouds.

Here’s how the system works in some of Collin County’s largest cities:

Frisco

Frisco’s 42 sirens can be activated citywide or in targeted clusters, providing more localized alerts. The city uses sirens for:

• Tornado warnings
• Severe thunderstorms with over 70 mph winds
• Hail 1.25 inches in diameter or larger
• Other threats as determined by public safety officials

Frisco also supplements alerts with government-access TV channels, police and fire vehicle speakers, and other communication systems. Sirens are tested monthly on the first Wednesday at noon, using the same “wail” tone used during actual emergencies.

Plano

Plano operates an expansive network of 43 outdoor warning sirens, managed by the city’s Emergency Management Department. Sirens may be activated for:

• Tornado warnings for the immediate area
• Severe thunderstorm warnings with winds over 70 mph
• Hail at least 1.5 inches in diameter
• Other emergencies like chemical spills or civil defense incidents

Plano tests its sirens at noon on the first Wednesday of each month, weather permitting.

McKinney

McKinney’s 29 sirens are managed by the office of emergency management and alert for:

• Tornado warnings naming McKinney in the projected path
• Large hail 1.5 inches or more
• Destructive winds over 70 mph
• Confirmed tornado sightings near the city
• Chemical or hazardous material threats

McKinney tests its sirens on the first Saturday of the month at noon, weather permitting.

Allen

Allen's 26 sirens are triggered by:

• Tornado warnings specifically mentioning Allen
• Hail larger than 1 inch
• Winds stronger than 70 mph

The city tests outdoor warning sirens at noon on the first Wednesday of every month.

Prosper

Prosper operates 11 outdoor sirens, with activation criteria including:

• Severe thunderstorm warnings with destructive winds
• Tornado warnings in or near Prosper
• Spotter-confirmed tornadoes
• Hail at least 1.5 inches in diameter
• Other emergency directives from the town’s emergency management team

Monthly testing occurs on the first Wednesday at noon, unless inclement weather is present.

Celina

With a smaller network of five sirens, Celina’s system is designed specifically for outdoor use. Activation occurs when:

• A tornado warning includes any part of Celina
• Severe thunderstorm warnings predict 70 mph winds
• Hail of 1.5 inches or more 
• Other significant emergencies arise

Like most other cities, Celina tests sirens on the first Wednesday of each month at noon, weather permitting.

The Bottom Line

Sirens in Collin County do not always mean a tornado is overhead, but they do always mean pay attention. The safest response when a siren sounds is to seek shelter and check a trusted weather source immediately. And remember: sirens are for people outdoors. Inside your home, it's wise to rely on a NOAA weather radio, smartphone alerts or other digital notifications for timely updates.

In storm season, knowing what sirens mean — and what they don’t — can make all the difference.

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