For the last week, India has sweltered under temperatures almost unimaginable to the rest of the world. We don't yet have a good accounting of how many people have died as a result, but the number is probably very high. This has culminated with Delhi, a city of 26 million, experiencing its all-time highest temperature on Monday at 48ºC (118ºF). India's recent history makes clear this is not an isolated event, but a product of human effects on the atmosphere, as well as localized urban heat islands.

The record was announced by the India Meteorological Department (IMD), based on recordings from the Palam Observatory. Meanwhile, the city's other observatory, Safdarjung, recorded 45.6ºC (114ºF), still easily lethal if, like most of India's population, you lack access to air conditioning.

Other parts of India have experienced even more intense heat as part of the same weather system. On June 1, Churu in West Rajasthan recorded 50.3ºC (123ºF). Two days later the same station exceeded 50ºC again. This fell just 0.2ºC (0.4ºF) short of the all-time Indian record, set in 2016. The country is still under a severe heat warning. 

In addition to the global climate catastrophe, the heat is a product of the late arrival of the monsoon. By this point in the year, southern and central India should be feeling the soothing effects of moist winds, but so far only small pockets have gained relief.

The late monsoon doesn't just pose a threat in terms of heat. Rainfall has been below average for most years over the last two decades and water supplies are drying up, with many villages dependent on tankers that do not bring enough to drink, or water livestock. There are reports of stabbings as people (and animals) fight for water, and this season's rainfall is expected to be low.

Delhi's previous temperature record was only 0.2ºC (0.4ºF) cooler, but it was set on June 9, 2014. The fact that high, but not low, temperature records are being broken so frequently is one of the ways we can tell this is not a purely natural event. Eleven of the 15 hottest years (including all the top six) India has experienced since record-keeping began occurred since 2004, the IMD announced. Last year was the sixth highest and this year will probably beat it.

Some Indian cities, led by Ahmedabad, have developed heat action plans, providing warning alerts, changing working hours when heat waves strike, and adjusting urban architecture so more heat is reflected and less absorbed. An assessment of the effectiveness of these plans credits Ahmedabad's actions with saving more than a thousand lives a year in a city a third Delhi's size. It remains to be seen whether similar plans can counteract the twin trends of greater heat and reduced water.