Happy Swiss Siren Day!

So I am currently visiting Switzerland, happily sitting in a café and coding away. All is nice and well. Except. In the distance looms a menacing shadow: It’s the first Wednesday of February… If you, like me, have not grown up in Switzerland (or lived there for some time), you’d be forgiven for thinking this is just a normal Wednesday like any other. But oh boy, how wrong you’d be!…

At about 13:30, an ear-piercing screech cuts through the air.

A year ago, when I was also visiting Switzerland, I was sitting in my SO’s flat when the same thing happened. Except, because the flat is quite well-insulated (and the windows were closed due to it being February), the same screech was a lot more quiet… My first thought was “Huh, that sounds almost like air-raid sirens. But I must be wrong; why would something like that be going off?” Only for me to open the window and discover that, yes, those were, in fact, air-raid-like sirens. Sounding all around the city.

If you’ve seen enough movies, or played enough video games, the sound is unmistakeable and hearing it in the real world, in what you know is not some form of fiction or entertainment, immediately instills a feeling of dread. My first reaction was to check various world news sites, just to check whether WW3 had somehow suddenly broken out. When that didn’t seem to be the case (and I started getting the adrenaline under control) I noticed that literally nobody else down on the street below seemed concerned. Either they’d made their peace with the impending doom a long time ago, or there was something I was missing. Assuming it was most likely the latter, I tried looking at the local news, but no luck there either. Finally, I did an online search for “Switzerland air sirens” (in retrospect, I probably should’ve done that a lot sooner in the process) and found a perfectly reasonable explanation on an online forum. I laughed a bit at the wave of relief that washed over me, and continued going about my day only slightly shaken.

It turns out that every year, on the first Wednesday of February, the Swiss test all their sirens. There are 2 types of these: flood sirens and general sirens. Testing these is, of course, an entirely reasonable thing to do when you have so many rivers, lakes, bunkers, precautionary military measures, several nuclear power plants, and lots of sirens. However, as far as I can tell, there is no announcement or news or warning or anything that this will be happening! Everyone “just knows” (tm). So if you, like me, have never been in Switzerland at just the right time and are just innocently going about your day like it’s any other, you get quite the nasty shock…

A year later, I now know to expect the sirens when I’m visiting in February. But it’s still an eerie sound, and I don’t think I’m going to get used to it anytime soon…

(Oh, and since you’re probably curious as to what it sounds like, here you go!)

Thomas Ekström Hansen
Thomas Ekström Hansen
PhD student in Computer Science

My interests include information visualisation, formal methods, and low-level programming.