Rising Heat: Bengaluru and Pune Transition from Cool Climates to Hot Zones

In April, Bengaluru experienced its second-hottest day in 50 years, while Pune is expected to reach temperatures between 40-42 degrees Celsius in the coming days. This April marked the first time in at least 41 years that Bengaluru received no rain. On April 25, the city recorded a scorching 38.5 degrees Celsius, marking its second-hottest day in half a century.

In recent years, cities like Bengaluru and Pune, known for their pleasant weather year-round, have been witnessing a concerning trend of rising temperatures. Residents have taken to social media platforms, expressing their need to purchase or rent air conditioners and coolers due to the escalating heat—a phenomenon previously unheard of in these metropolises.

So, what caused this shift in weather patterns, and was it sudden? 

Experts attribute this to the “Urban Heat Island Effect,” wherein urbanized areas experience higher temperatures than surrounding regions.  

The reasons

• Increase in construction and high-rise buildings

• Reduction in the cities’ blue and green covers

• Increased number of vehicles on the roads, and more roads as well

• Impermeable cities where the water doesn’t percolate below surface level (and hence doesn’t help in keeping the cities cool)

• Increased energy consumption and production inside the cities

• Ever-expanding cities

According to the United States Environmental Protection Agency, urban heat islands result from increased concretization, construction, and the proliferation of high-rise buildings in urban areas. Concrete absorbs heat during the day and releases it in the evenings, contributing to warmer temperatures even after sunset. 

Earlier, the evenings would bring cool breezes, offering relief from the daytime heat. However, trapped heat now radiates from concrete structures, elevating the overall temperature. To address this issue, experts emphasize the need to identify and protect vulnerable populations through targeted heat action policies.