Who Decides How Hot it is?

This summer seems to have been a hot one all over. Certainly, in China, the heat has been a popular topic of conversation the past few months. How hot is it really? Well, interestingly, it very much depends who you ask.

In Beijing, at least, there’s plenty of skepticism about the official temperatures that are reported. It’s a commonly-held belief that because the government and other employers are required to give some types of workers the day off or pay them extra if the temperature breaches 40 degrees Celsius (i.e., 104 degrees Fahrenheit), the officially reported temperature will never break 40℃, regardless of how hot it actually is.

This week’s issue of Southern Weekend has a cover story about the heat and how it’s reported:

On July 5th, a Beijing TV placed an uncooked egg on top of a manhole in the street. Three minutes later, it was fully cooked. On August 13th in Hangzhou, an alcohol thermometer was only on the street for a moment before it shot up beyond its highest marked temperature: 50℃.

The weather reports for those places from the day before suggested that the highest possible temperatures would be 32℃ and 37℃. The actual temperatures on that day were measured at 39.5℃ and 40.6℃ (respectively).

There have already been 23 heat-related sudden deaths in Beijing, Jinan, Wuxi, Hefei, etc.; half of these deaths were people working in outdoor trades [who can’t legally be made to work if the temperature is above 40℃] like construction or cleaning the outsides of buildings.

However, at the times these deaths occurred, none of the “highs” in these cities weather reports were as high as 40℃.

Needless to say, this has been a contentious issue online for some time. The Southern Weekend report quotes one netizen as asking, “So is whether or not it’s over 40℃ a science question or a political question?”

According to the report, China’s official temperature readings come from a thermometer suspended 1.5m off the ground in a wooden, ventilated box. Each city has one. Most countries use a similar system, which allows Chinese meteorologists to easy compare their numbers to others around the globe. However, the temperature on the ground can be much hotter than what these official thermometers register. For example, on August 5th in Guangzhou, the official thermometer never got above 37.1℃, but the ground temperature on the same day got as high as 51.8℃.

Another reason for the disparity is that these temperature measurements aren’t actually being taken in the city. While each city has one, according to the report many of them are not recording temperatures in the city proper, where a variety of factors from the prevalence of buildings to the increased amount of pollution combine to make the temperature rise. So when the Beijing weather report says 37℃, that means it’s 37℃ inside a ventilated wooden box 1.5 meters off the ground, somewhere outside (but near, presumably) the city itself.

Moreover, these temperature readings are just one factor that goes into producing the numbers you seen in weather forecasts, which are apparently hotly debated by teams of meteorologists. “The ‘highs’ and ‘lows’ of the daily weather forecasts are not the result of direct mathematical equation,” said expert Li Kaile, “they’re the result of a discussion between the meteorologists on duty at the time.”

Also, the numbers are not calculated to factor in the influence of humidity, wind speed, or relative solar radiation. To get a real idea of what the temperature the next day will be like, Southern Weekend says, you’d need to collect all of this information, and you’d also need a bit of meteorological expertise.

The article’s authors wondered: “Isn’t that a little bit difficult for common folks?”

All the experts Southern Weekend spoke to denied that there was any kind of threshold they weren’t allowed to pass at 40℃.

Whether the 40℃ rule is real or not, it seems clear that the weather forecasts here are totally useless for city dwellers. After all, very few of us spend our days in ventilated wooden boxes outside the city. But at least now we know if we ever want to, it will be easy to find out what the weather there is like…

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0 thoughts on “Who Decides How Hot it is?”

  1. Hello,
    Did you check http://www.weather.com.cn ?
    They seem to publish weather information by city districts so that should be inner city thermometer.

    Also they publish hourly mesure which could help you check if there is a bias by comparing with your personal thermometer.

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  2. This temperature increase is a global phenomena, even if it is a bit more pronounced in China, due to factors mentioned by Custer.
    I dare say the aforementioned discussion between metereologists to arrive at non-mathamatical number will involve a lot more semantic slippage as climate change begins to really bite.

    Look out for the Ministry of Propaganda official guidelines for temperature reporting being outed on the net.

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  3. I find the idea of regulating what is an acceptable working temperature quite amusing. Why can’t a management person simply take feedback from staff and make a decision based on the information and the work being done by those workers?

    If it is 40C outside, but I’m sitting in 21C in an office, it really makes no difference to me. If it is 35C outside and I’m laying hot tarmac for a new road in an area with no shade… then I would probably want to take frequent breaks and ensure I have enough fluid or maybe even call it a day a bit early.

    Why does the responsibility for all this lie with the government? I can’t recall laws of this kind in Australia or the UK. Does any one know of other countries with these direct and specific laws?

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  4. @ Leon
    (sorry about the last one Custer – computer error)
    I have a friend working in Kuwait, and apparently it’s the same deal there, although I think their temperature max is higher. Something like 45 or 50. I remember him telling me the exact same story – that the temperature will never be reported as being higher than that maximum.

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  5. “Another reason for the disparity is that these temperature measurements aren’t actually being taken in the city. While each city has one, according to the report many of them are not recording temperatures in the city proper, where a variety of factors from the prevalence of buildings to the increased amount of pollution combine to make the temperature rise. So when the Beijing weather report says 37℃, that means it’s 37℃ inside a ventilated wooden box 1.5 meters off the ground, somewhere outside (but near, presumably) the city itself.”

    I’m reaching a bit back into my memory of my high school and university days, but the information in this paragraph strikes me as being nothing unusual. I believe meteorologists have a set of rules about how to measure a proper air temperature designed to minimise the influence of things like buildings, wind and direct sunlight in the thermometers, and to not get it confused with things like ground temperature. I would hope, Mr Custer, that your summary is incomplete and that the original article does go into more detail about why the official thermometers are installed in ventilated wooden boxes 1.5 metres above the ground somewhere probably just on the edge of the city.

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  6. C Custer,

    Is it true that there are some extremes of how people measure temperature? Yes, yet the Southern Weekend article doesn’t explain that there are any political implications.

    Like

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