The city’s sky turned grey on Saturday afternoon, but the Met office clarified that it was not due to cloud cover but a haze formed by suspended particles.
Suspended particles include road dust that gets stirred up by vehicular movement and may also contain PM2.5 particulate matter.
Saturday morning was slightly colder than Friday by a whisker, marking the coldest of the season so far. The minimum temperature was recorded at 12.8° Celsius, one degree below the 30-year average, and 0.1° Celsius lower than Friday.
Early risers experienced the chill first hand, as the minimum temperature is recorded in the morning hours.
The afternoon, however, felt warmer than the previous day. The maximum temperature reached 22.9° Celsius, 2.5 degrees below the normal but 1.7 degrees higher than Friday.
“I had to take off my jacket. On Friday, I had to wear woollens even in the afternoon,” said a resident of south Calcutta.
Two men light a fire to keep themselves warm at BBD Bagh area
An official of the India Meteorological Department, Calcutta, explained that the rise in afternoon temperature was due to the early dissipation of morning fog.
“Fog prevents sunlight from warming the ground. When the shallow fog dissipates early, sunlight warms up the surroundings, causing a rise in temperature,” the IMD official said.
The haze of suspended particles remained visible across the city throughout Saturday.
Drivers on EM Bypass reported dense haze near Science City. “Tall buildings were partially obscured by the haze,” said a man who drove from Ruby to Salt Lake in the afternoon.
“It looked like cloud cover at first. I even thought it might rain,” said a Ballygunge resident. The IMD official clarified that the grey skies were caused by haze and not impending rainfall.
According to the forecast, the minimum and maximum temperatures on Sunday are expected to hover around 13° and 23° Celsius, respectively.
The mercury is likely to rise slightly from Monday, the Met office has said.