Dear Mr. Know-It-All,
OK, what on earth is going on with all these typhoon warning signals? How come we’re leaping from signal 3 to 8? What the heck happened to signals 2, 4, and 5? — Number Wonder

It wasn’t always signal numbers, my numerologically curious friend. Back in the day, the Hong Kong Observatory hoisted typhoon warning signals on top of the Tsim Sha Tsui police station, and a typhoon gun was fired to warn everyone of bad weather on the way. Between one to three shots would be fired to indicate the strength of the winds. In time, the gun was replaced by a cannon, and then by explosives. Sadly, this awesome system was abolished in 1937.

The typhoon signal system as we know it was introduced in 1917. Originally they were numbers 1 to 7, with numbers 2-5 denoting where gale force winds were coming from: so signal 2 was from the north-west, and 5 was from the south-east. Confusing, right? The system later changed to signals 1 and 5-10, with signals 5-8 standing for gales from each compass point. Eventually someone sensible decided that was all too complex, and since 1973 we’ve had signals 1, 3, 8, 9 and 10. Of course, signal 8 is still divided into 8 NW, 8 SW, 8 NE and 8 SE. But unless you’re a maritime adventurer, it’s not worth concerning your landlubberly head with.

At their peak in the 1960s, there were 42 typhoon signal stations across the territory, and during each typhoon, giant signals would have to be hauled to the top of poles for all to see. These days, a typhoon warning is merely a smartphone and the HKO’s hilariously detailed app away. (Seriously, it’s hilariously detailed. Look up the radiation levels across Hong Kong next time you’re checking the weather.)