Is there really a blazing sun in the tropics?

Solar irradiation graphic by William Connolley based on HadCM3 data.

The heat was growing worse and worse. April was nearly over, but there was no hope of rain for another three weeks, five weeks it might be. Even the lovely transient dawns were spoiled by the thought of the long, blinding hours to come, when one's head would ache, and the glare would penetrate through every covering and glue up one's eyelids with restless sleep. No one, Oriental or European, could keep awake in the heat of day without a struggle.  --George Orwell, Burmese Days TNR 16

Actually, the sun in SE Asia is not especially blazing, rather 50 to 75 percent blazing. George Orwell is not really talking about the heat of the sun in his novel/memoir Burmese Days, it's mainly really.... other stuff that make it so uncomfortable. We'll be looking at all that.

But for now, take a look at this map which shows how much energy actually reaches the earth on the average over a year. Thailand -- and much of SE Asia including Orwell's Burma, is about 200 watts per square meter over the year, the same as the US south and most of the central and South America.

And why aren't we seeing a smooth red belt of blazing heat right across the map in the tropical region between The Tropic of Cancer and The Tropic of Capricon? Because over much of the area, high water vapor including clouds are blocking 25 to 50 percent of the solar radiation. This potent factor may be enough to offset global warming in these regions.

Is there really a blazing sun in the tropics?

Solar irradiation graphic by William Connolley based on HadCM3 data.

The heat was growing worse and worse. April was nearly over, but there was no hope of rain for another three weeks, five weeks it might be. Even the lovely transient dawns were spoiled by the thought of the long, blinding hours to come, when one's head would ache, and the glare would penetrate through every covering and glue up one's eyelids with restless sleep. No one, Oriental or European, could keep awake in the heat of day without a struggle.  --George Orwell, Burmese Days TNR 16

Actually, the sun in SE Asia is not especially blazing, rather 50 to 75 percent blazing. George Orwell is not really talking about the heat of the sun in his novel/memoir Burmese Days, it's mainly really.... other stuff that make it so uncomfortable. We'll be looking at all that.

But for now, take a look at this map which shows how much energy actually reaches the earth on the average over a year. Thailand -- and much of SE Asia including Orwell's Burma, is about 200 watts per square meter over the year, the same as the US south and most of the central and South America.

And why aren't we seeing a smooth red belt of blazing heat right across the map in the tropical region between The Tropic of Cancer and The Tropic of Capricon? Because over much of the area, high water vapor including clouds are blocking 25 to 50 percent of the solar radiation. This potent factor may be enough to offset global warming in these regions.

Does the tropical sun rise in the east?

...and sink in the west?

Well not exactly, at least here in Bangkok in the hot season, April of every year. The illustration here which I made in the pub the other night shows this for June 21, summer solstice. It actually rises in the northeast and sets in the northwest, and that is a very important detail because it affects which condos get deadly solar heat at different times of the day.


Worth a book in itself? Maybe. It would have saved me a lot of discomfort, and money too, if I had understood this fifteen years ago. 

Does the tropical sun rise in the east?

...and sink in the west?

Well not exactly, at least here in Bangkok in the hot season, April of every year. The illustration here which I made in the pub the other night shows this for June 21, summer solstice. It actually rises in the northeast and sets in the northwest, and that is a very important detail because it affects which condos get deadly solar heat at different times of the day.


Worth a book in itself? Maybe. It would have saved me a lot of discomfort, and money too, if I had understood this fifteen years ago. 

What to wear at a hot and humid funeral, US style. But no flip-flops, please.

USA fashion website advice: These days, a sleeveless dress and bare legs is appropriate at most American funerals, especially when it’s a very hot climate. Consider a lightweight cardigan if there’s a service inside the house of worship and a hat to protect yourself from the sun at the grave site. If your shoulders are bared, your neckline should be very modest, the fit not too tight, and the hemline at the knee.

Reader Comment: One thing that set me off at my Dad's funeral was the minister, a woman in her 30s, in flip-flops. She had on a black robe and I imagine she thought since she had that on that her feet didn't matter. 

funeral entertainment in Asia

Now there will be those who disapprove of the lack of gravity here, but they would be more surprised at village funerals in Thailand, where rock bands and sexy dancers are the norm, or in Taiwan, where even nude dancing is OK.

What to wear at a hot and humid funeral, US style. But no flip-flops, please.

USA fashion website advice: These days, a sleeveless dress and bare legs is appropriate at most American funerals, especially when it’s a very hot climate. Consider a lightweight cardigan if there’s a service inside the house of worship and a hat to protect yourself from the sun at the grave site. If your shoulders are bared, your neckline should be very modest, the fit not too tight, and the hemline at the knee.

Reader Comment: One thing that set me off at my Dad's funeral was the minister, a woman in her 30s, in flip-flops. She had on a black robe and I imagine she thought since she had that on that her feet didn't matter. 

funeral entertainment in Asia

Now there will be those who disapprove of the lack of gravity here, but they would be more surprised at village funerals in Thailand, where rock bands and sexy dancers are the norm, or in Taiwan, where even nude dancing is OK.

Thermal misery index: Bangkok v Phnom Penh

Having spent some time in Phnom Penh over the past month, it seemed to me that the Cambodian city was much more hot and glaring than Bangkok. So today back in BKK I checked this by compiling one of my favorite indexes for the two cities: Extreme Cooling Degree Days (CDD29). This was derived from the excellent web site degreedays.net which allows you to calculate cooling degree days based on any temperature base you like. In this case I used a base of 29C (84F) which is the maximum allowable temperature for comfortable (sweat-free) sleeping IMHO.

Cambodian expats escribe PP as insufferable in the hot season (April-May) and the above graph suggests it is a little but not much worse than Bangkok at that critical time of year.

On the other hand PP has many fewer high-rise buildings than BKK, and the shading seems to me much less there, the sun penetrating down to street level. A more accurate comparison would require a careful comparison of downtown urban microclimates, and also, I conclude, consideration of the degree that uncomfortable glare aggravates the subjective sense of thermal discomfort.