Delhi AQI reaches 337 two days after GRAP Stage I curbs

Delhi’s Air Quality Index reached 337 at 9.31 am on October 23, two days after the Commission for Air Quality Management activated Stage I of the Graded Response Action Plan across the National Capital Region. India Today reported the reading, citing AQI.in data.

A reading of 337 falls in the Central Pollution Control Board’s ‘Very Poor’ category, which spans 301–400. Although the report initially described the reading as ‘Severe’, it subsequently identified the correct CPCB classification.

Air quality deteriorates overnight

The reported 24-hour AQI.in trend showed air quality improving during Thursday afternoon, when readings fell to approximately 110–115. The index then climbed through the evening, crossed 200 overnight and reached 337 on Friday morning.

CAQM had invoked Stage I on October 21 following a sharp pollution increase a day after Dussehra. Measures at this stage include controlling construction dust, mechanised road sweeping and action against open waste burning.

The subsequent rise shows that pollution continued to accumulate with those restrictions in place. It does not, by itself, establish how much the measures helped or what air quality would have been without them.

Winter trends raise questions about implementation

A Centre for Research on Energy and Clean Air analysis, reported on October 22, found no consistent improvement in Delhi’s winter air quality since GRAP was revised in 2022. The city’s average winter AQI increased from 280 in 2022–23 to 295 in 2025–26.

Across 12 pollution episodes examined, 10 had a higher average AQI in the week after stricter restrictions were introduced than in the preceding week. That comparison records continued deterioration after intervention, but is not a controlled measure of the restrictions’ effectiveness: weather and other factors can also affect pollution readings.

Implementation gaps were another concern. CAQM reportedly flagged shortfalls ranging from 7% to nearly 100% in several required measures during 2026, including construction-site inspections and road sweeping. Those figures concern gaps in carrying out mandated actions, rather than a measured percentage reduction in their effectiveness.