I checked weather.com this morning to see if I could get an accurate description for Mumbai. I was expecting a typical reading, such as partly cloudy, cloudy or sunny. What I got, however, is a new description of weather:

 

Smoke. The drawing was black squiggly lines.

 

There are cities in the world where simply walking around the city for a day is like smoking a pack of cigarettes. Throw heat into these cities and it is even worse.

 

I thought it would be interesting to do a comparative study of the biggest urban propers in the world and their associated climates. I will compare the results to the Mercer Consulting Best Cities of the World survey measuring the top standard of livings and wealth of cities. There are a variety of ways to do this study, but for simplicity's sake, I will take the January and July 24-hour average temperatures according to World Climate for the cities and compare it to the Mercer list. Here we go:

 

1. Mumbai, India; Population: 13.9 million; January = 74.5 F, July = 81.5 F

2. Shanghai, China; Population: 13.5 million; January = 34.9 F, July = 81.3 F

3. Karachi, Pakistan; Population: 13.0 million; January = 64.2 F, July = 86.4 F

4. Delhi, India; Population: 12.3 million; January = 57.4 F, July = 87.8 F

5. Istanbul, Turkey; Population: 11.4 million; January = 42.1 F, July = 73.9 F

6. Sao Paulo, Brazil; Population: 11.0 million; January = 70.2 F, July = 58.6 F

7. Moscow, Russia; Population: 10.5 million; January = 13.6 F, July = 65.3 F

8. Seoul, South Korea; Population: 10.4 million; January = 25.7 F, July = 75.9 F

9. Beijing, China; Population: 10.1 million; January = 23.7 F, July = 78.8 F

10. Mexico City, Mexico; Population: 8.8 million; January = 55.9 F, July = 62.1 F

11. Tokyo, Japan; Population: 8.7 million; January = 38.5 F, July = 76.5 F

12. Jakarta, Indonesia; Population: 8.5 million; January = 78.4 F, July = 79.3 F

13. New York City, USA; Population: 8.3 million; January = 37.9 F, July = 84.2 F

14. Lagos, Nigeria; Population: 7.9 million; January = 80.2 F, July = 77.2 F

15. Kinshasa, Congo; Population: 7.8 million; January = 77.4 F, July = 77.9 F

16. Tehran, Iran; Population: 7.8 million; January = 37.4 F, July = 85.3 F

17. Lima, Peru; Population: 7.6 million; January = 72.0 F, July = 61.3 F

18. London, U.K.; Population: 7.6 million; January = 42.6 F, July = 66.0 F

19. Bogota, Colombia; Population: 7.2 million; January = 54.9 F, July = 55.2 F

20. Honk Kong, China; Population: 7.0 million; January = 59.9 F, July = 82.8 F

 

The top five cities on 2009 Mercer Quality of Life Survey: Vienna, Zurich, Geneva, Vancouver and Auckland.

 

Of the 20 most populated cities in the world, only three appear on Mercer's top 50 list: Tokyo at 35, London at 38 and New York City at 49.

 

What is the relation? Well, if you notice from the figures, some cities don't have climate fluctuations while some do.  Some have climate fluctuations from harsh climates (below 30) to high temperatures (above 80). 

 

All three of these cities 1) fluctuate and 2) between the 30 and 80 temperatures with NYC being just a little higher (over 80).  No other city except Istanbul fits this description. This is an interesting conclusion that provides a unique twist to the geography hypothesis.