Kolkata has been shivering over the past few days, prompting social media to claim there is a cold wave in the city. However, the India Meteorological Department (IMD) says that while conditions are chilly, Kolkata is not officially under a cold wave.
“There is no cold wave alert for Kolkata. The maximum temperature is low, but a cold wave is declared based on minimum temperature, not how cold it feels during the day,” HR Biswas, head of the weather section at the Regional Meteorological Centre in Kolkata, told My Kolkata.
What is a cold wave?
According to IMD criteria, a cold wave in the plains is considered when the minimum temperature drops to 10 degrees Celsius or lower and the departure from normal is significant. A cold wave is declared when the departure from normal ranges between minus 4.5 degrees Celsius and minus 6.4 degrees Celsius. A severe cold wave is when the departure crosses minus 6.4 degrees Celsius. Alternatively, a cold wave can also be declared if the actual minimum temperature falls to 4 degrees Celsius or below, and a severe cold wave at 2 degrees Celsius or below. These conditions must persist in at least two stations in a meteorological subdivision for two consecutive days.
Why Kolkata does not qualify yet
Kolkata’s minimum temperature on Monday stood at 12.5 degrees Celsius, which is 1.7 degrees below normal, but above the cold wave threshold. “Some places like Bankura recorded minimum temperatures below 10 degrees, but that alone does not mean a cold wave for Kolkata or the entire region. Every year around this time, temperatures drop to similar levels,” Biswas said.
IMD’s south Bengal forecast also shows no cold wave warnings for Kolkata, Howrah or the 24 Parganas, with weather warnings marked as nil for the next seven days
Current weather and what to expect
The local forecast for the next 24 hours indicates a partly cloudy sky with shallow fog at night and during the morning. The maximum and minimum temperatures are likely to hover around 19 degrees Celsius and 12 degrees Celsius, respectively. Day temperatures are expected to remain 3 to 5 degrees below normal across Gangetic West Bengal for the next few days, while minimum temperatures may fall by about 2 degrees before stabilising
“The cold may feel intense, but officially, this is not a cold wave,” Biswas reiterated.