Chennaiites who fret over warm day temperatures often reach out for winter clothing in the nights for the past four days. The minimum temperature at Meenambakkam dropped to 18.6 degree Celsius on Wednesday night, the lowest in the past three decades during March.
Night temperature has remained at least two or three degree Celsius below normal temperature for a few days now.
Similarly, the weather station in Nungambakkam recorded 22 degree Celsius, two degree Celsius lower than normal temperature on Wednesday night. But, the day was relatively warmer with maximum temperature touching 33 degree Celsius on Thursday.
According to IMD data, the minimum temperature had dipped as low as 18.2 degree Celsius in Meenambakkam on March 1, 1989. Nungambakkam has experienced its lowest minimum temperature of 18.8 degree Celsius in 1976.
S.Balachandran, Director, Area Cyclone Warning Centre, said such diurnal temperature variation in 24 hours is typical during transition period between March and April. Though the day temperature climbs up faster, night temperature dips as land gets cooler fast.
Trend to continue
Some places like Vellore and Tiruttani have recorded 17 degree Celsius and 15 degree Celsius. Such weather trend will continue for a few more days.
Officials of the meteorological department said normally the diurnal variation is around 7-8 degree Celsius. But on Wednesday night, the variation was more than 14 degree Celsius, and that is a rare phenomenon. Normally, such weather pattern is less in coastal stations.
Weather bloggers of Chennai Rains note that after 15 years, Chennai airport has experienced a cold night in March wherein the minimum temperature had dropped below 19 degree Celsius. Earlier, the suburb recorded 18.8 degree Celsius in March 1992.
Weather expert Y.E.A.Raj said normally, duration of day time will get longer in March. Uninterrupted incoming solar radiation, clear sky and less moisture content in the atmosphere led to warm days and quick cooling of land during night hours. This led to faster dip in minimum temperature during the transition season. Interior areas away from the sea would experience more colder nights.
