Two prolonged heatwaves, a missed cyclone and wet spells, March ends as a month of extremes

The first heatwave spell lasted between March 11-21 and the ongoing spell, which commenced on March 26, will continue to affect Delhi, Rajasthan, Himachal Pradesh, Haryana, east Uttar Pradesh, Madhya Maharashtra and Odisha till before it abates around April 5.

“The frequency of heatwaves over India peaks in May but there can be heatwaves in March in some areas of the Central India regions between Gujarat and Odisha during the seasonal transition between winter and summer. But this March, the number of heatwave days was significantly larger than usual and its geographical expanse was more as it reached the foothills of the western Himalayan along with Rajasthan and Delhi—adding to the discomfort as early as mid-March,” said Mrutyunjay Mohapatra, director general, IMD.

Mohapatra added, “Some meteorological stations reported a 7 to 9 degrees rise in the maximum temperatures from normal.”

In fact, a man reportedly succumbed to heatstroke in the Jalgaon district of Maharashtra, which has been reeling under heatwave since early this week. Chandrapur in Vidarbha recorded 44.2 degrees on Wednesday and remained the hottest city in India on the day. This was for the first time since 1901 when Chandrapur recorded such heat in March, the IMD’s temperature data suggested.

Mohapatra attributed the prevailing severe heatwave conditions in March to two main factors—lack of strong western disturbances passing along North India and the steady and continuous inflow of warm winds from Southern Pakistan over Northwest India.

“In the absence of western disturbance, there are no cold winds blowing over the North and Northwest India. That is why, when warm winds originating from the high pressure cell located over Pakistan are able to reach Gujarat, Rajasthan all the way to Himachal Pradesh, Uttarakhand and even Jammu,” explained Mohapatra.

The rainfall over these regions, too, has been appreciably below normal, making it dry and hot, he added. Similar dry days are forecast in April, making it a continuing heating condition for Northwest and Central India regions in the days ahead. This year, the country witnessed 13 heavy rainfall events (when 24 hours rainfall is between 64.5mm and 115.5mm) while in 2021 and 2020, these events were 13 and 44, respectively.

Till March 30, the all-India rainfall for the month stood at minus 72 per cent, one of the driest March in recent decades. This is opposed to minus 35 per cent in March 2021. The highest rainfall deficiencies in March this year was reported from Northwest (minus 89 per cent) and Central India (minus 86 per cent) regions.

Thunderstorms, which include lightning and light to moderate rainfall, too, have been largely absent over most parts of the country this March, the IMD officials noted. Thunderstorms in March are common over South India and Northeast India. “Rainfall associated with thunderstorms have been reported only over southern peninsular regions and it has not been the case in the east and northeast India regions,” Mohapatra said.

As a result, East and Northeast India ended with rainfall deficiency of 59 per cent while southern peninsula remained 13 per cent rain deficient in March.