You almost cannot under-dress, in Hong Kong.

Jeans and T-shirts are standard men’s wear. Unless it’s particularly hot. Then anyone out and about (but not going to work) is wearing T-shirts and shorts — especially if he is under 30.

I like this. I arrived with a batch of polo shirts, a pair of cargo pants and a couple sets of jeans … and I’ve become a borderline fashion-plate.

I’m a little surprised by this.

I thought of Hong Kong, always, as an international financial center. All those bankers wearing all those severe suits.

And there is a dollop of that. Especially in the Central district, where the money (and the bankers) can be found.

But the rest of the city … the guys running the tiny shops might well be wearing a wife-beater-style undershirt, slippers and some grubby pair of slacks. When he’s done for the night, you might see him walking down the street with his shirt off entirely.

I’m pretty sure this is about the weather.

Hong Kong is a tropical city. (That is, it lies between the tropics of Cancer and Capricorn.) It’s warm and muggy here about eight months a year. And horribly warm and muggy about six months a year.

You don’t wear a lot of clothes in a place like that. Comfort trumps style.

Think “Hawaii” — where sandals, shorts and a, yes, Hawaiian shirt are standard fare … and you’re getting closer.

The women try a bit harder. Though you can see plenty of them wearing jeans and T-shirts. (Albeit nicer T-shirts than the guys.)

Anyway, I brought two coats, three long-sleeved white shirts and three ties with me. And I realized by, oh, Day 2, that I wouldn’t be needing much of any of that.

Restaurants don’t seem to mind how you dress, and the local citzenry doesn’t give the evil eye to you if you’re wearing shorts and flip-flops.

This is good, for me. I’m not into formal wear. And my idea of informal turns out to be something approaching high fashion, here.

Put that on the lengthy list of “didn’t see that coming” events.