All over the Netherlands, the public warning sirens are tested on every first Monday of each month at 12.00 noon. The siren is quite loud and it takes 1 minute and 26 seconds.

Public authorities check the siren to see if it works properly. Therefore, the siren is a test siren and it rings twice. However, if you hear it repeatedly more than twice, it means there is an emergency then you should follow the instructions and advice of the public authorities. Also, If you hear the siren at another time, you should go indoors immediately.

On the government website, you can find more information about what you should do in case of an emergency siren.