Minambakkam, the base station observatory of Chennai recorded a maximum temperature of 41.3°C yesterday. This mercury level with 7°C above the normal amounts to severe heatwave condition. Unlike inland stations where the heatwave is announced only after the temperature touches 40°C, coastal station like Chennai qualify this feat even at 37°C. There has been a steady rise in the temperature over the last 4 days and the mercury has climbed from 34.7°C on 27th March to 41.3°C on 30th March.
All-time record of March was established on 29th Mar 1953 when the observatory registered a temperature of 40.6°C and now the fresh reading beats the earlier one hollow with a clear and sufficient margin of 0.7°C. Such an oppressive heat is not at all common to see in the capital city of Tamil Nadu sharing coastline with the Bay of Bengal. The highest temperature in the month of March invariably stops short of 36°C with some freak occurrence overshooting this threshold. The highest maximum for Chennai of 39.2°C was scaled on 31st March 2019. The previous year 2020 remained rather comfortable with the highest mercury level of 34.7°C on 04th March.
Many a time, the threshold of 40°C is not breached even in the month of April and the last 3 years (2018-2020) did not record even a single event. Yes, the month of May is frequented with temperatures above 40°C for Chennai, particularly in the 2nd half of the month. Incidentally, May and June are the hottest months with sweltering heat and torrid summer.
This week is going to be very hot and humid for Chennai and mercury is likely to stay above 40°C for the next 4-5 days. The temperature today may cross even yesterdays record and mercury may skyrocket to breach 42°C at Minambakkam in the 1st week of April. Pre-monsoon trough, a semi-permanent feature is extending from Coastal Andhra Pradesh to South Tamil Nadu along the coast with an embedded cyclonic circulation. This feature is going to persist and suppress as well as delay the onset of sea breeze. The temperature is expected to rise till 2 pm - 2.30 pm and drop thereafter with the arrival of an onshore breeze.