Delhi’s air quality remains ‘poor’; minimum temperature dips again

Meteorological experts said consistent winds and bright sunshine during the day on Sunday with very little fog helped the dispersion of pollutants in the national Capital

Delhi’s air quality remained in the “poor” category on Monday a day after dipping below 300 for the first time in 32 days even as minimum temperature dipped again. An average air quality index (AQI) of 272 was recorded at 9am on Monday, a dip from 4pm reading of 285 on Sunday. Delhi earlier recorded “poor” category AQI on October 29 when it was 268.

None of the 38 air quality stations online were in the “severe” zone at 9am on Monday. (HT PHOTO)

Meteorological experts said consistent winds and bright sunshine during the day with very little fog helped the dispersion of pollutants. The conditions were expected to remain favourable until at least Wednesday. Monday’s minimum temperature of 10.4°C was a degree above normal. It was a degree lower than Sunday’s minimum of 11.4°C. Cold northwesterly winds were expected to pick up speed by Wednesday and cause further dip. The minimum was 9.8°C on Saturday. The season-low of 9.5°C was recorded on Friday.

“There have been consistent dry northwesterly winds since Saturday with wind speeds of around 8 kmph. Winds picked up to speeds of 15 kmph during the day on Sunday which helped in the dispersion of pollutants. There was also no dense fog in the region...there has been adequate sunshine during the day, which again helps in pollutants and gases dispersing as the mixing height is fairly high,” said private weather forecaster Skymet meteorology vice president Mahesh Palawat.

None of the 38 air quality stations online were in the “severe” zone at 9am on Monday. Nehru Nagar recorded the highest AQI of 336 (very poor) and six other stations over 300. Chandni Chowk had the lowest AQI at 188 (moderate).

Pollution levels worsen in Delhi in November with an average AQI of 374. The Capital has recorded eight “severe” air days in 10 days. The average AQI touched as high as 494 on November 18, the joint second highest in the Capital. The first severe air day was recorded on November 13 and the last on November 23. A reduction in fog intensity and stubble contribution has improved the air quality.

The CPCB classifies AQI between 0 and 50 as “good”, 51 and 100 as “satisfactory”, 101 and 200 as “moderate”, 201 and 300 as “poor”, 301 and 400 as “very poor”, and over 400 as “severe”.