The world is getting warmer | The number of days with a temperature above 35 degrees is growing unstoppably

The London-based International Institute for Environment and Development (IIED) has published an analysis quantifying the growing threat of extreme heat in some of the world’s largest urban centres.
The number of days on which the temperature reaches 35°C in the world’s 20 largest metropolises, from Delhi to Jakarta to Buenos Aires, has increased by 52 percent over the past three decades, the think tank’s analysis reveals.

More than 300 million people live in the 20 most populous capital cities, where they are uniquely vulnerable to the rise in temperature caused by climate change given the fact that asphalt and buildings absorb and retain heat.

Capital cities including Delhi, Dhaka and Manila have already been hit by dangerous heatwaves this year, causing high numbers of heat-related deaths and school closures.

Delhi witnessed its longest and most intense heat wave in 74 years, with 39 consecutive days of maximum temperatures above 40°C from May 14 to June 21, according to the weather station.

The London-based International Institute for Environment and Development (IIED) has published an analysis quantifying the growing threat of extreme heat in some of the world’s largest urban centres.

Using surface temperature data from airport weather stations, the researchers found that from 2014 to 2023 there were a total of nearly 6,500 days or occasions when the temperature in one of the 20 cities reached 35°C or more. In the decade from 1994 to 2003, that number was just 4,755.

We know that hot weather is not felt equally in different cities, said Tucker Landesman, an IIED researcher.
Pockets of extreme heat are more likely in certain types of neighborhoods and commercial areas. It has to do with inequality and the way we design buildings and public infrastructure.

Indonesia’s capital, Jakarta, experienced the largest absolute increase in the number of days with temperatures above 35°C, from 28 days between 1994 and 2003 to 167 days in the last decade.

Seoul in South Korea went from nine days to 58, and Buenos Aires from seven to 35.