Delhi's seasonal battle with toxic air remains fundamentally stagnant, with government air quality metrics showing no consistent improvement over the past four winter cycles despite aggressive emergency interventions.
According to an evaluation conducted by the Centre for Research on Energy and Clean Air (CREA), winter air pollution across the National Capital Region (NCR) continues to oscillate without establishing a downward trajectory. The assessment reviewed official data recorded since the revision of the Graded Response Action Plan (GRAP) in 2022, revealing that recent seasonal pollution levels exceed those logged four years ago.
Metric Fluctuations Expose Policy Gaps
The study analyzed both the mean and median Air Quality Index (AQI) readings, two statistical measures that help smooth out short-term meteorological anomalies such as unseasonal rain or severe temperature drops.
In the winter of 2022–23, the capital logged a mean AQI of 280. This figure deteriorated to 304 in 2023–24, dropped to 285 in 2024–25, and climbed back to 295 in the 2025–26 winter period. Median AQI measurements tracked an identical pattern, moving from 294 to 324, decreasing to 289, and escalating back to 305.
"Delhi’s winter air quality has not followed a consistent downward trend since the 2022 revision of GRAP, and the mean and median AQI for the latest winter were both higher than in 2022–23," stated Manoj Kumar, an analyst at CREA. The findings highlight that episodic emergency curbs, designed to restrict specific vehicular movements and construction activities during peak pollution spikes, are failing to generate cumulative, year-round air quality dividends.
Delhi Winter AQI Comparison (Four-Year Trend)
| Winter Cycle | Mean AQI | Median AQI | Primary Status Classification |
|---|---|---|---|
| 2022–23 | 280 | 294 | Poor to Very Poor Baseline |
| 2023–24 | 304 | 324 | Very Poor (Significant Spike) |
| 2024–25 | 285 | 289 | Poor (Marginal Seasonal Relief) |
| 2025–26 | 295 | 305 | Very Poor (Rebound) |
Atmospheric Factors and Persistent Baseline Emissions
The Commission for Air Quality Management (CAQM) relies on four escalating stages of GRAP based on prevailing and forecast air quality across Delhi-NCR. However, winter meteorology across the Indo-Gangetic Plains inherently compounds human-driven emissions.
Plunging surface temperatures create atmospheric inversion layers, while lower wind speeds prevent the horizontal dispersion of pollutants. These meteorological realities, combined with regional agricultural stubble burning during October and November, festive firecracker emissions, and consistent year-round pollution from transport and industry, routinely swamp reactive curbs.
Demonstrating the persistent vulnerability of the capital's airshed, monitoring stations recorded a 24-hour average AQI of 223 at 4 p.m. on Thursday, maintaining Delhi in the 'poor' air quality band for a second consecutive day, as tracked by the Central Pollution Control Board.
