Old Spice

Last year the makers of "Old Spice" deodorant for men published the results of a study of the "sweat rankings" of American cities. The winner was Phoenix Arizona but Texas cities like Dallas and Houston and several Florida cities were right up there and since I've always had a bad memory of Houston I'm going to use that place as a kind of bench mark, to compare Boston and Bangkok.


Take a look at the "march of temperature" through the seasons in three cities: Boston, which had a famous heat wave the first few days in August, 2006 (pink circle), a hundred thirty six people died including one woman sitting inthe bleachers at Fenway Park; Houston, which as I said seemed to me to be really awful, and Bangkok, awfuller yet. The red points are the highest temperature of the day, the green the highest dew point temperature of the day (more on that later). When the temperture is more than 30, you will begin to sweat, even if you are just sitting looking at this blog.

As you can see, that's most afternoons in Bangkok (the daily high is usually at about three o'clock).

You might say that Boston heat wave got up as high as Bangkok, but even thoughthey were passing out cold water on the half deserted Boston streets you could still sweat pretty effectively there because the dew point temperature was low, down around 24. In Bangkok, in contrast, the dew point hardly gets below 26 most of the year, so all that sweat just soaks your shirt and hardly cools a body at all.

Normal Year?

A couple of weeks ago a Thai lady said to me "The heat hasn't been bad this year, a couple of weeks in March or April, then the rains cooled things down and it hasn't been bad since."

This lady happened to be an experienced architect, and my sense of the year agreed with her comment, but as a "quant" I felt compelled to look at the data, so I loaded Don Muang daily highs (temp and dew point) and superimposed on the hottest year I've found, which happens to be 1983. To my surprise this suggested that 1983 wasn't really so bad after all, except that the hot season got a little prolonged (so it just kept getting hotter) and then finally broke with the rain which (if I am right in my thinking) came a little late. I also believe that 1983 was a bad flood year, so now I wonder wheher al these things are tied together.