Cold wave abates, fog delays flights, trains amid severe pollution levels

Delhi’s Air Quality Index (AQI) deteriorated to 449 (severe) at 9am on Monday because of calm winds, low temperature, and fog

Cold wave conditions abated in the northern plains with Delhi’s weather representational weather station in Safdarjung recording a minimum temperature of 6.4°C on Tuesday even as dense fog delayed flights and trains amid severe pollution levels.

Flights were delayed between 12:30am and 6am. (HT PHOTO)

The Commission for Air Quality Management in NCR was expected to hold a review meeting on the implementation of stage IV of the Graded Response Action Plan.

Delhi’s Air Quality Index (AQI) deteriorated to 449 (severe) at 9am on Monday because of calm winds, low temperature, and fog. On Monday, an AQI of 434 was recorded as per Central Pollution Control Board’s 4pm national bulletin and prompted the Commission to enforce a ban on BS-III petrol and BS-IV diesel vehicles in Delhi.

Monday’s AQI was a sharp deterioration from Sunday’s reading of 371 (very poor). It was the poorest air quality logged in the city since November 4, when the AQI reading was 447 (severe).

The city on Monday recorded its fifth consecutive cold wave day with a minimum temperature of 3.8°C, three notches below normal.

The temperature recorded at Safdarjung on Tuesday was a notch below normal but 2.6°C degrees higher than on Monday.

The visibility dipped to 50 metres at Palam and Safdarjung due to “very dense” fog and disrupted train and flight operations.

No diversions or cancellations were reported at the Delhi airport even as flights were delayed between 12:30am and 6am. The northern railways said at least 35 trains were delayed by over an hour.

Other weather stations also reported a rise in the temperature by 2-3°C. Palam recorded a minimum temperature of 7.5°C, Lodhi Road 6.4°C, and Ridge 4.3°C.

A cold wave is declared in the region when the minimum temperature is 4.5°C or more below the normal, or when it drops to 4°C or lower.

Safdarjung recorded five consecutive cold wave days from January 5 till January 9, making it the longest for January since five such days were recorded in January 2013.

The mercury plunged to 3°C degrees on January 5, 4°C on January 6, 2 2°C on January 7, and the season’s lowest of 1.9°C on January 8. The minimum temperature increased to 3.8°C on January 9.