Chennaiites woke up to an unusual chill on Wednesday morning, with the minimum temperature dropping to 20 degree Celsius in the city and 18.7 degree Celsius in Meenambakkam.
While it was hazy in the city, the suburbs, particularly those in the south, were covered in a shallow fog and mist.
The difference between mist and haze is the difference in visibility levels, with the former being heavier.
Smoke pollutants from garbage burning at the Perungudi dumping yard since Sunday, lingering in the atmosphere, coupled with the high humidity levels, might have contributed to the fog in the southern suburbs seen on both Tuesday and Wednesday, meteorologists said.
Residents of various areas said the nights have been growing colder as the week advances. Travelling in sparsely-populated areas during the night was becoming difficult without some form of protection against the cold, residents said.
February, which started on a warm note, is becoming cold, going by the minimum temperature recorded at weather observatories.
The night temperature dropped from nearly 25 degree Celsius on Saturday to 20 degree Celsius on Wednesday. Last year, the minimum temperature in the city had dropped to 19.5 degree Celsius on February 25.
However, the day temperature continued to be slightly above normal on Wednesday. Nungambakkam and Meenambakkam registered 31 degree Celsius and 32.6 degree Celsius, nearly two degrees higher than average temperature for this season, officials of the meteorological department said.
Y.E.A. Raj, deputy director general of meteorology, Chennai, said the clear sky had led to warm days and cold nights in the city. Prompt setting in of the land breeze early in the morning also contributed to radiation cooling and misty mornings.
Chennai will experience comfortable days until mid-February, after which both the day and night temperature will gradually increase, he said.
Officials at the Aerodrome Meteorological Office (AMO), Meenambakkkam, said that normally, fog forms around 5 a.m. and dissipates within two hours. But on Wednesday, a fog remained over localities close to Chennai airport until 8 a.m.
R. Suresh, director, AMO, said the visibility level had reduced to 700 metres in the southern suburbs.
The department has forecast misty or foggy mornings for two more days.
