Delhi’s air quality was in the “very poor” category for a third straight day on Tuesday, but strong surface-level winds helped disperse pollutants, pushing the Capital’s air to the verge of the “poor” zone by late in the night.
The city also reported shallow fog in the early morning hours, before visibility improved later in the day, with the Capital recording cloudless, sunny skies.
Delhi’s average air quality index (AQI) figure at 7am was at the brink of the “severe” zone with a reading of 395 (very poor). However, AQI had improved to 343 by 4 pm — when the Central Pollution Control Board (CPCB) shares its daily national bulletin — on the back of winds with speeds up to 15kmph, further improving to 317 by 7pm and 306 by 10pm.
By 11pm, the average AQI in Delhi was 304, but at least 15 ambient air quality monitoring stations had entered the “poor” zone. Meanwhile, Noida, Greater Noida and Faridabad had entered the “moderate” zone, while Gurugram and Ghaziabad were at the lower end of the “poor” spectrum.
Forecasts by the Centre’s Early Warning System for Delhi (EWS) show the Capital’s AQI should remain in the “very poor” category on Wednesday as well, before deteriorating back to the “severe” category by Thursday as the wind speeds drop.
“Winds picked up on Tuesday during the day and helped disperse pollutants. On Monday, they were mostly calm and we saw a deterioration through the day and visible smog,” said Mahesh Palawat, vice president at Skymet meteorology.
Palawat added that a western disturbance is likely to impact the region around November 29, thus slowing down wind speed from November 28. “When a western disturbance starts to influence the region, winds become stagnant and so there may be deterioration in AQI from November 28. again,” he said.
Delhi has already recorded eight “severe” days this November — much worse than the three such days recorded in November 2023, and fast closing in on the 11 such days in November 2022.
Meanwhile, Delhi recorded a maximum temperature of 26.7 degrees Celsius (°C) on Tuesday, which was around normal for this time of the season, India Meteorological Department (IMD) said. The minimum was 11.9°C — 0.6 degrees above normal. IMD forecasts show the maximum and minimum should hover around 27°C and 11°C, respectively, on Wednesday.
