Kolkata residents endured another bone-chilling day on Sunday as a thick blanket of fog and persistent cold winds gripped the city, sending the mercury plummeting. The maximum temperature recorded was a mere 19.2 degrees Celsius, marking a significant drop and continuing a recent trend of unusually cold days in the metropolis.
Fog Disrupts Day-Night Cycle, Temperature Gap Shrinks
The day's weather was dominated by dense fog, which blocked sunlight for most of the day. This phenomenon caused a remarkable narrowing of the gap between the day's high and low temperatures to just 4.3 degrees Celsius. The minimum temperature settled at 14.9°C, which was actually 0.9 degrees above the normal level for this time of year.
This was the third instance in a single week that Kolkata's maximum temperature fell below the 20°C mark. It was also the second time the difference between the maximum and minimum temperatures contracted to less than 5 degrees, indicating the fog's powerful effect on the daily thermal cycle.
Meteorological Factors Behind the Chill and Fog
Meteorologist Sourish Bandyopadhyay from the Regional Meteorological Centre explained the science behind the conditions. "The day temperature dipped as persistent fog kept the sun at bay for most of the day," he stated. The combination of fog and low cloud cover was attributed to increased moisture levels in the atmosphere.
This moisture incursion into the Gangetic belt was triggered by a cyclonic circulation over Bangladesh. Simultaneously, a western disturbance over north-western states hampered the flow of dry, chill-bearing north-westerly winds into the region over the preceding days, allowing the moist, foggy conditions to establish.
Historical Context and Forecast: More Cold Ahead
The current spell evokes memories of a similar severe episode this winter. On December 29, the city's maximum temperature had plunged to 18.2°C, the lowest in over 15 years, due to comparable foggy conditions. The gap between maximum and minimum that day was 4.7°C.
While temperatures had seen a gradual rise after December 30, they remained below 20°C for two consecutive days thereafter. The season's lowest minimum of 11°C was recorded on New Year's Eve.
Looking ahead, the weather office predicts a revival of cold conditions across Kolkata and much of south Bengal. Although the maximum may hover around 20°C on Monday, the minimum is expected to fall to 13-14°C. Meteorologist Bandyopadhyay indicated that the north-westerly winds are regaining strength. "We can expect the mercury to start falling again," he warned, adding that shallow to moderate fog might persist but may not be very prominent at the surface level on Monday.
