Most parts of India are reeling under a severe heat wave currently, said multiple reports. This year, the heat wave spell has already stretched for 32 days, the second-longest spell ever recorded, according to Hindustan Times. In 1988, there were 33 such days, and in 2016, there were 32 such days.

Four cities in North India reported record-high temperatures on Monday. The maximum temperature in Churu, Rajasthan, crossed 50 degrees Celsius while Banda in Uttar Pradesh touched 49.2 degrees Celsius. Allahabad sizzled at 48.9 degrees, while Delhi touched 48 degrees.

A heat wave is declared in large areas when the temperature touches the 45-degree Celsius mark for two days straight while a severe heat wave is declared when the mercury records 47 degrees for two consecutive days. However, a heatwave is declared in a place such as Delhi after the mercury touches 45 degrees Celsius for a day.

Monsoon usually sets in over Delhi on June 29 but the Met department said last week that it would be delayed by two to three days. Skymet predicted that monsoon rains in Delhi in might be delayed by a week.

Heat waves have been become frequent over the last few years. Since 2004, the country has experienced 11 of the 15 warmest years, reported NDTV. DS Pai, a scientist with the India Meteorological Department, said a study of long-term heatwave data of 35 metrological sub-divisions showed a threefold increase in heatwaves every year since 1991. “Our observation indicates that the increase was steeper in the last two decades,” he told the Hindustan Times.

Since 2010, more than 6,000 people have died in heat waves across the country, Health Minister Harsh Vardhan had told the Lok Sabha in 2018. On Monday evening, four elderly passengers on Kerala Express travelling to Coimbatore in Tamil Nadu died in Uttar Pradesh’s Jhansi district because of extreme heat.