Cold wave worsens; mercury plunges to season’s lowest 3.3°C

The cold wave worsened on Monday as the mercury plunged four degrees below normal to 3.3°C, the lowest this season so far, in Delhi even as dense fog enveloping the Capital reduced visibility to zero at Palam for around two hours and disrupted air traffic. The minimum temperature has remained below 4°C since Friday.
The India Metrological Department (IMD) declares a cold wave when the minimum is 4.5° or more below the normal. Cold wave in the plains is also when the minimum temperature is below 4°C for two consecutive days. A minimum temperature of 3.6°C was recorded on Saturday and 3.9°C on Sunday
An IMD official said the visibility was zero at the airport between 3am and 5:30am before improving marginally to 50 metres. “Dense fog continues but the intensity is not as bad as Sunday.”
Four flights were diverted to Jaipur and one to Ahmedabad. Over 50 flights were delayed in the early hours of Monday. The season’s worst fog on Sunday delayed over 400 flights, caused 10 diversions, and around 20 cancellations.
The air quality improved a day after this year’s first severe air day on Sunday prompted the Commission for Air Quality Management to invoke stage-3 measures of the Graded Response Action Plan for mitigation.
An average Air Quality Index of 386 (very poor) was recorded at 9am on Monday compared to 447 (severe) at 4pm on Sunday. It was likely to remain very poor until January 18.