Delhi AQI slips below GRAP-3 threshold of 350

New Delhi: Delhiites woke up to 'very poor' air on Tuesday, with the city's AQI touching 344 and four stations reporting 'severe' pollution levels, the Central Pollution Control Board (CPCB) data showed.

Out of 37 monitoring stations, Bawana (426), Wazirpur (412), Jahangirpuri (418) and Vivek Vihar (402) were in the 'severe' range.

According to the forecast, the air quality is expected to remain in the 'very poor' category over the next few days.

Last week on Tuesday, the Centre invoked stricter anti-pollution measures under Stage III of the Graded Response Action Plan (GRAP) in Delhi-NCR after the city’s air quality slipped into the ‘severe’ category.

The decision was taken after Delhi’s average Air Quality Index (AQI) rose sharply from 362 on Monday to 425 on Tuesday morning due to calm winds, a stable atmosphere and unfavourable weather conditions that allowed pollutants to accumulate close to the surface, the Commission for Air Quality Management (CAQM) said.

As the AQI slips below the GRAP-3 threshold of 350, Delhiites may expect the curbs to be lifted.

Earlier, GRAP-3 was linked to the “severe” AQI band of 401–450, but a Supreme Court order in late 2024 directed the Commission for Air Quality Management to start imposing Stage-III measures once the city’s average AQI touches around 350 and is on a rising trend, so that tougher curbs begin before pollution enters the extreme range.

Since then, CAQM has been invoking or revoking GRAP-3 based on whether Delhi’s AQI is above or safely below this 350 mark.

An AQI between 0 and 50 is considered "good", 51 to 100 "satisfactory", 101 to 200 "moderate", 201 to 300 "poor", 301 to 400 "very poor" and 401 to 500 "severe", as per the CPCB classification.

On the weather front, the minimum temperature settled at 9.6 degrees Celsius, 2.7 notches below the season's average, and the maximum temperature is likely to hover around 26 degrees Celsius.