Delhi AQI remains ‘very poor’, likely to stay for the week

Forecasts by the Centre’s Air Quality Early Warning System (EWS) for Delhi shows the AQI should firmly stay “very poor” in the days ahead.

The air quality in the city remained in the “very poor” category on Sunday and is expected to remain in the zone throughout the week. The 24-hour average air quality index (AQI) was recorded at 308 on Sunday, as per the Central Pollution Control Board’s 4pm data. It was 330 (very poor) on Saturday.

The average AQI on Sunday was recorded at 308. (Sanchit Khanna/HT Photo)

Delhi’s air quality has largely stayed in “very poor” range this winter, with three consecutive “severe” air days between November 11 and 13. Forecasts by the Centre’s Air Quality Early Warning System (EWS) for Delhi shows the AQI should firmly stay “very poor” in the days ahead.

According to categorisation by the CPCB, an AQI reading between 0-50 is “good”, 51-100 “satisfactory”, 101-200 “moderate”, 201-300 “poor”, 301-400 “very poor”, and 401-500 “severe”.

“Delhi’s air quality is likely to be in the ‘very poor’ category from December 8 till 10. The outlook for the subsequent six days from December 11 onwards also shows the air quality is likely to be in the ‘very poor’ category.”

Mahesh Palawat, vice president at Skymet, said no significant change in the weather conditions is likely till December 10. “There will be no significant change in the AQI. It may improve when winds pick up briefly, but not enough for complete dispersion,” he said.

Meanwhile, the minimum temperature of the city rose on Sunday due to the impact of a prevailing western disturbance. It was recorded at 8 degrees Celsius (°C), which was two notches below normal and up from 6.8°C on Saturday and season’s low of 5.6°C on Friday. An increase in moisture has led to partially cloudy skies, which traps heat at night and raises the minimum.

The India Meteorological Department (IMD) has forecast the minimum to rise further on Monday – hovering between 9-11°C. A dip in minimum is only expected from December 11.

“It will remain between 8-11°C till Wednesday, before possibly hovering around 6-8°C on Thursday and Friday,” an IMD official said, stating strong winds of 15-20 km/hr may be seen briefly during the day on Monday.

The maximum temperature was logged at 24.7°C on Sunday as against 24.6°C the previous day.

The IMD had earlier forecast isolated coldwave conditions to persist in parts of northwest India till December 5, owing to cold northwesterly winds blowing from snow-clad mountains to the plains. The minimum was 5.7°C on December 1, which was the coldest start to December since at least 2011.

Typically, Delhi’s minimum dips below 5°C in December, but this usually happens in the second half of the month. The lowest minimum last December was 4.5°C (December 12 and 16). In 2023, it was 4.9°C (December 15). It was 5°C in 2022 (December 26); 3.2°C in 2021 (December 20); 3.1°C in 2020 (December 31) and 2.4°C in 2019 (December 28).