Delhi AQI to slip into 'poor' category from Wednesday, pollution levels to rise

The city's air quality index (AQI) was recorded at 179 on Tuesday, placing it in the moderate category.

Delhi recorded a maximum temperature of 31.8 degrees Celsius on Tuesday, while the national capital's air quality is expected to deteriorate to the poor category from Wednesday, according to the Air Quality Early Warning System.

The city's air quality index (AQI) was recorded at 179 on Tuesday, placing it in the moderate category. However, forecasts indicate that pollution levels are likely to rise over the coming days as the winter pollution season approaches.

Delhi's air quality likely to remain poor until October 23

According to the Air Quality Early Warning System, Delhi's AQI is expected to enter the poor category from Wednesday and remain there until October 23. The outlook for the following six days also suggests that air quality is likely to continue in the poor category.

The system noted that unfavourable meteorological conditions could hamper the dispersal of pollutants. A ventilation index below 6,000 square metres per second, along with an average wind speed of less than 10 kmph, is considered unfavourable for the dispersion of pollutants.

Delhi last recorded poor AQI on July 13

The last time Delhi's air quality slipped into the poor category this season was on July 13, when the AQI stood at 246.

If the latest forecast holds, Wednesday will mark the first day of poor air quality in the national capital in 100 days, signalling a possible deterioration in pollution levels ahead of winter.

How is AQI classified in India?

According to the Central Pollution Control Board (CPCB), the AQI is classified into six categories based on pollution levels.

- Good: 0–50

- Satisfactory: 51–100

- Moderate: 101–200

- Poor: 201–300

- Very poor: 301–400

- Severe: 401–500

Meanwhile, Safdarjung, the city's base weather station, recorded a maximum temperature of 31.8 degrees Celsius, 0.8 degrees below normal, while the minimum settled at 17.7 degrees Celsius, 0.7 degrees below normal.

Palam recorded a maximum temperature of 29.3 degrees Celsius, 3.5 degrees below normal, and a minimum of 17.3 degrees Celsius, 1.6 degrees below normal.

At Lodhi Road, the maximum temperature was 31.4 degrees Celsius, 0.6 degrees below normal, while the minimum was 17 degrees Celsius, in line with the seasonal average.

The Ridge recorded a maximum temperature of 31 degrees Celsius, 2.3 degrees below normal, and a minimum of 18.5 degrees Celsius, one degree below normal.

At Ayanagar, the maximum temperature settled at 31 degrees Celsius, 2.1 degrees below normal, while the minimum was 18 degrees Celsius, 0.8 degrees below normal.

No rainfall was recorded at any of the five weather stations between 8.30 am and 5.30 pm on Tuesday, according to the India Meteorological Department.