You can review different sites on the internet and get different answers, grab the first one you see, copy and paste. For example, there's one city that's being touted as the hottest but that's based on a single temperature recorded in 1922, which hardly qualifies it as the hottest city in the World in reliance on one temperature. But more than that, the Asker wants a city which Al Aziziyah was not then and can hardly be considered more than a town today. The World Meteorological Organisation says. Bangkok, Thailand is the world's hottest city. Other cities like Rio may reach higher temperatures but Bangkok rarely cools down, tending to remain largely above 30 deg C from day to night, summer to winter.Another source says:10 Hottest Cities Average Temperature (deg.F) (deg.C) 1. Timbuktu, Mali 84.7 29.3 1. Tirunelveli, Tamil Nadu, India 84.7 29.3 3. Khartoum, Sudan 84.6 29.2 3. Omdurman, Sudan 84.6 29.2 5. Madurai, Tamil Nadu, India 84.0 28.9 5. Niamey, Niger 84.0 28.9 7. Aden, Southern Yemen 83.9 28.8 8. Tiruchirapalli, Tamil Nadu, India 83.8 28.8 9. Madras, Tamil Nadu, India 83.5 28.6 10. Ouagadougou, Upper Volta 83.5 28.6 The Guinness Book of Records says many different things, it may be viewed here:
http://hypertextbook.com/facts/2000/...mlAccordingly, I think we should go with what the World Meteorological Organisation says as it is the most reliable and scientifically source and they base their pick on many decades of records.Therefore, as your question did NOT ask for the hottest one day recorded temperature but instead asked for the averages the best answer is Bangkok, year in and year out. And Bangkok fits every definition of a city. .You also asked for high/low and Bangkok will often remain the same overnight.