The Grimes Brief

Guide · Safety

How Grimes gets tornado and severe weather warnings.

Iowa storm season is real, and Grimes sits across two counties, so it helps to know exactly how you will be warned and how to get an alert that reaches you indoors. Here is the plain guide.

The short version

Grimes is covered by the Polk and Dallas county outdoor warning sirens, which sound for tornado warnings and severe storms with winds of 70 mph or more. Sirens are for people outdoors, so also sign up for Alert Iowa to get warned inside.

The sirens

Outdoor warning sirens

The sirens are run by county emergency management, and because Grimes straddles the line, your siren is on the Polk or Dallas county system depending on your address. Both sound for a National Weather Service tornado warning or a severe thunderstorm warning with 70 mph or greater winds. They are meant to alert people who are outside to get indoors and check for more information, not as an all-clear or an indoor alert.

Siren issues: Polk County EMA 515-286-2107, Dallas County EMA 515-993-9894. Dallas County tests sirens the first Saturday of the month at noon.

Get alerts indoors

Don't rely on the siren alone

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Sources: Polk County Emergency Management; Dallas County Emergency Management; Alert Iowa. Confirm current siren policy and sign up for alerts through your county. Preview build, September 2026.