The Public Warning System will be used to warn of attacks from the air, land or sea, as well as natural and other man-made disasters. The table below shows what the various signals mean. It would be a good idea to memorise them.
Click on the "Play" button of the different types of Public Warning Signals to hear how it sounds
| Signals | How It Sounds* | Situation | What It Means |
| "Alarm " Signal | This is sounded when an air raid or shelling is imminent. | Move to a shelter immediately. | |
| "All Clear " Signal | This is sounded when the threat is over. | You can leave the shelter. | |
| "Important Message " Signal | This is sounded to alert the population to an important broadcast on the radio. | Tune in immediately to any local FM radio station or TV channel. |
Annually, the SCDF will be sounding the "Important Message" signal through the island-wide network of PWS sirens on 15 February and 15 September at 6:20pm. Do not be alarmed by the minute-long sounding exercise.
The signal will also sound for 20 seconds on all smartphones that have the SGSecure mobile app. This will be accompanied by a brief text message on the PWS sounding. To receive the signal and the text message, the app's notification and alert settings must be enabled.
When you hear the "Important Message" signal, tune in immediately to any local radio station or TV channel for a two-minute message on the PWS.
The annual sounding and broadcast message are part of the SCDF's continuous efforts to familiarise the public with the PWS signals and to raise awareness on how the public should react upon hearing the signal.
SGSecure for Iphone users
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SGSecure for Android users
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Contact us for more public education materials on the Public Warning System.