In Hong Kong you always need a sweater

It looks like the weather has changed here in Hong Kong. While just a few weeks ago I was wearing my coat (yes, one needs a coat in the tropics), I am now contemplating the prospect of bare legs and arms and wondering if I will ever feel comfortable in a swim suit again. This morning it is already 78° F and it is only 9:30. Ironically, the human ecology of this place means that even while I am quite warm enough sitting in our flat, if I go out I will have to take a sweater with me.

Yes, that is correct, one always needs a sweater in Hong Kong, whatever the weather. Let me explain. First, Hong Kong is very seasonal. This came as a real surprise to me. I am told by longer term residents that this last winter (the one I have been moaning about) has been particularly long and cold. Indeed, this is partially confirmed by the Hong Kong Observatory (great web site for those of you interested in climate and weather stuff--see http://www.hko.gov.hk/contente.htm), which says that while February was not cooler than usual, January and March were certainly colder (and drier) than normal. Mean temperature this last March was 64° F. I know this sounds warm, but bear in mind that it is also quite humid here and so feels a bit colder. Also, there is NO central heating--anywhere. That is right, none. And, since the buildings are concrete it is often the case that it is colder inside than it is outside. So if you run to the cold side, like me, a sweater is definitely needed. What is more, there were some days last month when the temperature was only about 54° F. March was a bit warmer overall than January and February. You are probably beginning to get the picture. While the colder temperature has certainly been a regular talking point, but the last time this point came up one of our friends did say that she thought this was a common feeling every year. I think the message is that if one is planning a trip to Hong Kong in the winter months, bring something warm to wear just in case. I’ve seen any number of tourists shivering away in their shorts and tank tops. If you are moving here you should definitely bring at least some of your warm clothes, and your slippers, with you. Of course, alternatively, you could just buy what you need when you arrive!

While the climate explains why a sweater is needed in the winter months, what about the rest of the year? While Hong Kong does not have a mechanical fix for cold weather, it overcompensates for the possibility of heat by the extensive use of air conditioning. I say possibility because often even when it is quite cold outside, the air conditioning will be running. This is certainly the case with my office. Some days I needed gloves it was so cold. While it is not a sure thing that the AC will be on when it is cold, it is a certainty that it will be on when the temperatures do reach about 70° F. What is more, there is AC everywhere: on the buses, in the taxi, in buildings, on the MTR. About the only public place that I can think of that has an inside that is not air conditioned is the tram (or the Ding Ding as it is called locally). Of course this means that one dresses for the outside temperature and then brings a sweater along to accommodate the inside and its rather different climatological conditions.

I learned recently that the standard temperature for Air Conditioning to be set is about 68-72° F for working environments. This is a fairly universal setting world wide, though is harder to control in large open spaces like shopping malls. What I found particularly interesting was the fact that this setting is based on something called “thermal comfort”, which means a normal person wearing a normal amount of clothes is neither too hot or too cold. So who is this normal person and what are normal clothes. Well it turns out that the normal person is a man and, according to my quick google scholar search, men have, on average, higher resting metabolic rates than women. Moreover according to the speaker who was talking about such things, the expectation of normal clothing is based on a suit. So the normal male wearing a business suit should be comfortable in this temperature. Of course they could take off the suit coat, we could turn down the AC and the contribution to climate change, at both the local/immediate and global/long term scales, would be less extreme. Apparently the Japanese are thinking about this as a way to help reduce their CO2 emissions. Seems a pretty easy fix, perhaps there is a campaign here somewhere...