String of heatwaves pushes temperatures to dangerous levels

For the second month in a row, temperatures in India and Pakistan are abnormally high because of a string of strong and prolonged heat waves – and now another surge is building.

This week, an intensifying heat wave is pushing temperatures to dangerously high levels.

Temperatures topped 110 degrees in the Indian capital of Delhi on Thursday, local time. The city of Nawabshah in Pakistan hit 47.5 degrees Celsius) – the hottest temperature in the Northern Hemisphere this year so far.

The heat wave has heightened the fire danger in recent days, threatened crop yields and even accelerated melting of some glaciers. While this part of the world is no stranger to extreme heat, scientists say conditions have been worsened because of climate change.

‘‘Heat waves happen more frequently now and they are spread around throughout the year,’’ said Amir AghaKouchak, a professor at University of California, Irvine, in an email. ‘‘This is the new normal and most likely it will only get worse in the future unless we take serious actions.’’

The India Meteorological Department has placed much of that nation under a ‘‘heat watch’’ through the weekend, with some locations like Madhya Pradesh in the centre of the country one step higher at ‘‘heat alert.’’

Temperatures in this episode are expected to peak over the next few days, although the hot temperature regime over the subcontinent seems entrenched, with, it appears, little meaningful relief in sight.

Most of India and a large area of Pakistan spent Thursday scorching under temperatures ranging between 40 and 45C. Between the two countries, nearly 1 billion people roasted under these extraordinary temperatures.

More than three dozen locations in India recorded temperatures of 45C or greater, including the sprawling capital of Delhi, where readings rose as high as 46C at the sports complex. Its official high was 43.5C, its highest April temperature in 12 years, according to the India Times.

The heat is expected to escalate at the weekend.

It’s probable that Pakistan ends up with the highest temperatures overall. Some locations north of the capital of Karachi could hit 49C or higher through the weekend. Forecasts for Jacobabad, known as one of the hottest cities on Earth, are as high as 50C, which could test major records.

According to Maximiliano Herrera, an expert on world weather extremes, the highest April temperature in India is 48.3C, reached in Barmer during 1958.

Nawabshah, Pakistan, about two hours inland from the Arabian Sea, hit 50.2C four years ago. – Washington Post