Delhi's air quality slipped into the 'very poor' category for the first time this season on Monday, with the Air Quality Index recording 312 at 9 am. This reading triggered Stage 2 of the Graded Response Action Plan. Meanwhile, the minimum temperature at the Safdarjung weather station settled at 16.4 degrees.

Delhi's air quality has plummeted to the 'very poor' category for the first time this season on Monday, with an AQI of 312, activating Stage 2 of the Graded Response Action Plan to combat escalating pollution levels.

IMAGE: Delhi implemented new vehicle entry restrictions from November 1, barring non-BS-VI compliant petrol and diesel vehicles from outside the capital.Photograph: ANI video grab

Key Points

* Delhi's air quality entered the 'very poor' category on Monday, marking the first time this season.

* The Air Quality Index (AQI) recorded 312 at 9 am on Monday.

* This 'very poor' AQI triggers Stage 2 of the Graded Response Action Plan (GRAP) in Delhi.

* GRAP Stage 2 involves strict measures to curb air pollution, decided by the CAQM.

* Minimum temperatures were also reported, with Safdarjung at 16.4 degrees Celsius.

Delhi's air quality slipped into the 'very poor' category for the first time this season on Monday, with the Air Quality Index (AQI) recording 312 at 9 am, while the minimum temperature at the Safdarjung weather station settled at 16.4 degrees Celsius, 1.1 notches above normal.

Understanding Delhi's Air Quality Status

The minimum temperatures at other weather stations were recorded at 16.4 degrees Celsius at Palam, 16.8 degrees at Lodhi Road, 17.2 degrees at the Ridge and 16.7 degrees at Ayanagar, according to the India Meteorological Department (IMD).

No rainfall was recorded at any of the five weather stations during the 24 hours ending at 8.30 am on Monday.

The AQI reading of 312 is the morning reading and not the day's average, which will be available at 4 pm, according to the Central Pollution Control Board (CPCB).

According to the CPCB, an AQI between zero and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe'.

Graded Response Action Plan (GRAP) Stage 2 is applied in Delhi when the Air Quality Index (AQI) enters the "Very Poor" category, ranging between 301 and 400.

The Sub-Committee for Operationalisation of the GRAP, ie, the Commission for Air Quality Management (CAQM) decides to invoke Stage 2 based on dynamic air quality and meteorological forecasts, include strict measures to curb air pollution.