With the southwest monsoon yet to become active, most parts of Tamil Nadu continue to experience extended summer and reel under heatwave-like conditions. Chennai is simmering with this month being the second hottest June on record in this decade.
Meteorologists expect southwest monsoon to slowly pick up pace in the next few days as Cyclone Biparjoy makes a landfall and begins to weaken. Most parts of the State may have to endure hot weather this week.
Thursday turned out to be yet another scorching day as temperature breached 40-degrees mark at many places, including Chennai, Madurai, Erode, Cuddalore and Vellore and made it dreadful for people to venture out during the day. For the 12th day this month, mercury level climbed above 40 degrees Celsius in Nungambakkam, creating a record after June 2019 when the city had 14 hot days.
Rain expected
S. Balachandran, Additional Director-General of Meteorology, Chennai, India Meteorological Department, said an uptick in rain is expected over the State from June 18 as a wind shear zone is likely to form. Conditions are more favourable for monsoon to advance in more parts of south peninsular region from Saturday.
There are possibilities for 16 districts, including Erode, Vellore. Kancheepuram and Tiruvallur, to receive heavy rain in isolated places between June 18 and 20. Heat may gradually relent over the State from next week, he said.
Weather experts noted that real-time heat could be felt more depending on the localities and distance from the coast. They attributed prolonged hot weather this June to strong westerlies that did not allow sea breeze to blow across the land and sustained high mercury level till almost evening and delayed onset of southwest monsoon.
Y.E.A. Raj, retired Deputy Director-General of Meteorology, Chennai, said the impact of urban heat island could be more in densely populated areas with more high-rise buildings and vehicular traffic compared to those with greenery where temperature level might be one degree Celsius less.
Similarly, proximity to sea would mean a lower day temperature and those localities away from the coast would record a higher temperature. More research is needed to analyse precise effect of ‘urban heat island’, he said.
In June, the normal number of hot days should be 4.7 in Chennai, going by the data between 2001 and 2019.
However, this June has surpassed the average number of hot days due to late onset of monsoon and lack of monsoon clouds, he added.
