The IMD long term temperature anomaly analysis indicate a trend of 0.62°C degree increase in temperatures over the Indian sub continent every 100 years. The four out of the five hottest years have been since 2010. While 2023 was the second hottest year, the hottest year was 2016 which was immediately after one of the strongest El Nino years in recent times. Devolving El Nino years like 2016 are known to be warmer than normal on account of the pent up heat the oceans gradually release while cooling down from El Nino conditions. Though 2023 did not reach the record levels of 2015 indications are 2024 could once again see record heat.
Peninsular India certainly had one of its warmest winters in recent years as not only coastal places like Chennai did not have any active spell of winter even interior places like Bengaluru hardly had a spell of biting cold nights. Gradually the day time temperatures have also started rising with the IMD observatory at Erode and Karur Paramathy coming very close to recording the first 40°C of Peninsular India last week. In a way the dry weather conditions during February has brought about an increase in day time temperatures under fairly clear skies. The last few days saw weak moisture pushed across by Easterlies bringing some isolated rains to places in Delta and South TN. This also meant the temperatures were kept under check as well over large parts of Peninsular India. Overall though February has seen scanty are nil rains across most IMD meteorological sub divisions in Southern Peninsular India.
Sub seasonal models indicate most of March, in particular the first fortnight of March, to be fairly dry across the region except for pockets along the Western Ghats. This spell of dry weather will not only bring about increase in day time temperatures on account of clearer skies but also gradually increase the ground heat thereby making the days hotter with each nudge in day time temperatures as we get to the second half of March. There is increasing consistency among models about the first 40°C of 2024 among the IMD observatories is a matter of days and not weeks.
Unlike the short spell of spike in temperatures last week which saw increase in temperatures over West Interior TN, the upcoming increase in temperatures may also reflect in places closer to Chennai as well with North interior TN also likely to see an appreciable increase in temperatures later next week. It may not come as a surprise if some of the western suburbs of Chennai records 37 / 38°C degree by second half of next week. Coastal areas may benefit from the Easterlies but the humidity may make it very uncomfortable during afternoons.