Faster winds provide Delhi reprieve from ‘severe’ air

On Friday morning, the AQI was 395 (“very poor”) at 9am, which further improved to a 24-hour average of 387 by 4pm, according to the CPCB’s daily bulletin

Faster winds on Friday helped slightly improve Delhi’s air quality, providing reprieve from three consecutive days of “severe” air and bringing it down to the upper-end of “very poor” air quality index (AQI), according to the Central Pollution Control Board (CPCB).

Morning smog at the Dwarka railway station in Delhi. (Vipin Kumar/HT Photo)

On Friday morning, the AQI was 395 (“very poor”) at 9am, which further improved to a 24-hour average of 387 by 4pm, according to the CPCB’s daily bulletin. The AQIs over the past three days were 428, 418, 404, all in the “severe” zone.

The CPCB classifies an AQI of 51 to 100 as “satisfactory”, 101 to 200 as “moderate”, 201 to 300 as “poor”, 301 to 400 as “very poor”, and a reading above 400 as “severe”.

Mahesh Palawat, vice president at Skymet, a private forecaster, said, “The wind speed has picked up and was around 14-15kmph throughout Friday, as compared to around 8-9kmph a day before. This helped disperse pollutants to some extent. The wind speed is expected to stay consistent on Saturday as well, with the direction varying between northwest and west.”

According to data from the Centre’s Decision Support System (DSS), the contribution of stubble burning also decreased on Friday, to 8.54%, as compared to 12% on Thursday.

Forecasts by the Air Quality Early Warning System (AQEWS) for Delhi suggest that the AQI is expected to be in the “very poor” category over the weekend. “The air quality is likely to be in the very poor category from Saturday to Monday. The outlook for the subsequent six days is that the air quality is likely to be in the very poor to severe category,” the AQEWS bulletin on Friday evening read.

On the day, Delhi recorded a minimum temperature of 10.2 degrees Celsius (°C), a minor drop from 10.6°C recorded a day before. This was 3.3°C below normal, according to the India Meteorological Department (IMD). The maximum temperature was 26.4°C, 2.1°C below normal.

“Mainly clear skies will persist over the weekend, with mist or shallow fog enveloping the city in the morning hours. As the temperature drops further, moderate fog might be seen in isolated places in the morning hours from the next week,” an official with the India Meteorological Department (IMD) said.

According to IMD forecasts, the minimum temperature might drop below 10°C over the weekend, and the maximum temperature is expected to stay between 24 and 26°C over the weekend before dipping further.