Mumbai records temperature of 41 degrees; heat wave to continue

Mumbai recorded one of the highest-ever maximum temperatures in March at 41° C on Sunday. It was 8.2° C above the climatological normal maximum temperature for March, 32.8° C. The presence of an anti-cyclone, or a high pressure area which pushes hot air downward towards the ground and lets it diverge on to surrounding areas, over Gujarat and Rajasthan heated up certain areas more than expected. 

“Temperatures were appreciably above normal today. This is a severe heat wave-like condition, and it would prevail for the next 24 hours,” K S Hosalikar, deputy director-general at Regional Meteorological Centre, Mumbai, said. 

Heat waves due to anti-cyclones in north India are a regular phenomenon during the April-May period, as are cyclones in the Indian Ocean. Occurrence in March is very rare, but possible, according to meteorologists. 

The 2001-2010 period saw 98 heat waves across India, compared to 48, 45, 34 and 74 in the decades before, showing a marked increase in heat waves in the first decade of the 21st century. Around 4,620 deaths were reported in four years from 2013 to 2016. Meteorological researchers have, too, statistically found a higher incidence of anti-cyclones in March in recent years, and some meteorologists attribute this to climate change. Some states, including Gujarat and Odisha, have started taking preventive actions.

In the current case of Mumbai, lower level (closer from ground) hot winds blew in a clockwise direction (which is the case for all anti-cyclones in the northern hemisphere) in a reverse C-shape path starting from Rajasthan and ending in Mumbai. “The sea breeze that normally sets in at 1 pm daily in summer set in at about 3 pm today (Sunday),” Hosalikar added. Hot easterlies delayed the incidence of sea breeze in Mumbai on Sunday.

Higher temperatures were recorded in the interiors according to data from a weather station network set up by private meteorological firm SkyMet all over Maharashtra. Places, including Thane, Panvel and Pen recorded close to 42-43° C, Skymet data showed. All-time maximum temperature for Mumbai in March was on March 28, 1956, at 41.7° C, followed by 41.3° C on March 17, 2011.