Rain, strong winds bring slight respite to Delhi’s bad air; airport ops hit

On account of bad weather in Delhi, 16 flights were diverted – ten to Jaipur, three to Lucknow, one to Ahmedabad and two to Amritsar.

The temperature also fell by a few notches Monday evening, standing at around 16.8 degrees Celsius at 8.30 pm, down from a maximum temperature of 24.2 degrees Celsius recorded during the day.

While calm conditions that have been prevailing in Delhi-NCR have prevented the dispersion of pollutants and kept the AQI in the upper end of the ‘very poor’ category or the ‘severe’ category over the past week, the wind speed picked up on Monday, hitting a maximum speed of around 20 kmph at Palam and 12 kmph at Safdarjung.

With this, particulate matter levels saw a marginal fall at some stations in the city. At Mandir Marg, the PM10 level fell by more than half, from 427 µg/m3 at 9 am on Monday to 207 µg/m3 at 9 pm, data from the Delhi Pollution Control Committee (DPCC) shows. Similarly, the PM 2.5 level at Mandir Marg fell from 300 µg/m3 at 9 am to 158 µg/m3 at 9 pm.

The AQI, calculated as a 24-hour average, remained at 391, in the upper end of the ‘very poor’ category, at 9 pm, with some stations like those at RK Puram, Punjabi Bagh, and ITO continuing to record 24-hour average AQI in the ‘severe’ category, going by data from the Central Pollution Control Board.

The impact of the western disturbance, which lay as a cyclonic circulation over central Pakistan on Monday, is likely to be felt in Delhi-NCR only till Monday night, said Kuldeep Srivastava, scientist, IMD. Light winds of around 8 kmph are expected in Delhi on Tuesday, he added.

No rainfall is expected in Delhi for the rest of the week, the minimum temperature could be around 11 or 12 degrees Celsius and the maximum temperature is set to be around 24 or 25 degrees, going by the IMD forecast.

According to a forecast issued by the Air Quality Early Warning System for Delhi, the AQI is set to remain in the ‘very poor’ category all through the week. The city has seen a severely polluted November so far, with 10 days when the AQI has been in the ‘severe’ category.

Light rainfall earlier this month had offered some respite from pollution levels, till the city saw a deterioration in air quality from the day after Diwali onwards.

So far in November, Delhi has recorded around 17.3 mm of rainfall, till 8.30 pm on Monday. The normal or long-period average for the month is only around 6 mm.