Computerworld Singapore - Why you don't get taxis in Singapore when it rains?

It is common experience that when it rains, it is difficult to get a cab in Singapore-even when you try to call one in or use your smartphone app to book one.
Why does it happen? What could be the reason behind it?
Most people would think that this unavailability of taxis during rain is because of high demand for cab services.
Well, Big Data has a very surprising answer for you, as astonishing as it was for researcher Oliver Senn.