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> Extreme heat (including heat waves that exceed this threshold) happen semi-regularly

The threshold is wet bulb 35 for 7 hours. That is when fit young humans can't survive. Older people die well before that of course.

And no, it doesn't happen regularly. I wasn't aware it had happened at all, although others here say it has. But it has come close. From https://www.telegraph.co.uk/global-health/climate-and-people... :

> Jacobabad crossed the 35C wet bulb threshold in July 1987, then again in June 2005, June 2010 and July 2012. Each time the boundary may have been breached for only a few hours, but a three-day average maximum temperature has been recorded hovering around 34C in June 2010, June 2001 and July 2012.

These people don't have the escapes you mentioned. They are in a city with no running water and no cars, let alone car parks. There is no river, but there are a couple of small lakes.



Here's a discussion of heat index and wet-bulb temps, with records from around the world.

https://www.wunderground.com/blog/weatherhistorian/record-de...

The most dangerous / frequent occurrences seem to be measured in the middle east near shallow gulf coasts. Appleton Wisconsin holds the continental US record, apparently?

This is from 2011.

This looks more updated: https://www.weather.gov/jetstream/hi

and says:

> The highest dew points, and therefore the highest heat indices are usually found near warm bodies of water.

> In the world, the warmest water is found in the Persian Gulf where the water temperature typically reaches up to 90°F (32°C) in summer. Therefore dew points will be that high as well.

> The highest dew point ever recorded, 95°F (35°C), was recorded at Dhahran, Saudi Arabia, on July 8, 2003. With an air temperature of 108°F (42°C) the heat index was 178°F (81°C).

> In the United States, the highest dew point ever recorded, 90°F (32°C), was recorded at the New Orleans Naval Air Station, on July 30, 1987, Melbourne, Florida on July 12, 1987. Heat indices were in the 130's°F (50's°C).

> Appleton, Wisconsin also had a 90°F (32°C) dew point on July 13, 1995 with a heat index of 149°F (65°C)."

So, it happened once, in Saudi Arabia?


> Jacobabad crossed the 35C wet bulb threshold in July 1987, then again in June 2005, June 2010 and July 2012. Each time the boundary may have been breached for only a few hours, but a three-day average maximum temperature has been recorded hovering around 34C in June 2010, June 2001 and July 2012.

Jeez what a hot place... Any idea what geographic features make it so dang hot? It's not too far from water (just looking at a map).


I lived about a hundred miles from Jacobabad in 1987. It was known as the hottest place in the world then along with Sibi to the north. I remember 50C temperatures but it was dry and I used to walk outside to the market around noon. Once my school principal saw me walking without a hat that summer and lectured me about safety but I didn’t feel anything bad. It helped that I was thin and had a high surface are to volume ratio so heat never bothered me. My father worked for Exxon and we had free electricity and every house had massive 8-ton air conditioners, so the heat was never a problem for us.

Sibi is in a hollow formed by some mountain ranges to the north. Perhaps hot winds from the south get trapped there. Not sure about Jacobabad though…could never find any reason why it was so hot.

Another time I was in a car with no AC right after a rainstorm, and it was so hot in the backseat that every time the car stopped the heat became unbearable. When the car was moving we had some wind and it helped.

In Canada I’ve always noticed the temperature can be 5-10 degrees cooler under trees in a forest. Not sure if it’ll be so cool with high humidity but certainly trees will block the sun and trap air cooled by the ground, so they are the best defence against global warming.


Thanks for sharing!


What city doesn't have running water?


The city can have running water while some people living there don't. Slums or homeless encampments are common the world over in large cities.

It means some people simply have no means to escape such heat and will likely die.

In the US, they sometimes open cooling centers during heat waves so homeless people and poor people have a place to go. I never went to such but they did that in Fresno and bus rides were free if you said you were going to a cooling center.


Many cities I would think. My spanish teacher lives in a big city in Venezuela and they use water tanks and electricity is rationed.


Lots. Many cities have running water for only a few hours a day.

And there may often be only one tap per 100 people in densely populated slums.


I’m pretty sure Jacobabad has cars.


Some people having cars != everyone having cars.


But the claim wasn't everyone having cars, it was "They are in a city with ... no cars."


If 1% of people have access to cars it’s pretty close to “no cars”.




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