Delhi records cleanest air in 6 months, GRAP restrictions lifted

Delhi recorded its cleanest air in six months , with the Air Quality Index (AQI) improving to 119 in the ‘moderate’ category, prompting authorities to lift all restrictions under the Graded Response Action Plan (GRAP) across the National Capital Region. The milestone marks a significant seasonal shift after over 150 days of sustained pollution controls.

According to the Central Pollution Control Board, the 24-hour average AQI fell to 119 on Monday, the lowest since October 9, 2025, when it stood at 99 in the ‘satisfactory’ range. Morning readings briefly touched 97, indicating ‘satisfactory’ air quality a rarity in recent months.

The sharp improvement was driven by light rainfall and favourable meteorological conditions triggered by a western disturbance on Sunday. The drizzle, coupled with stronger surface winds and better atmospheric mixing , helped disperse accumulated pollutants. The easing of winter conditions - typically marked by temperature inversion and stagnant air - also contributed to the cleaner air.

With AQI levels remaining well below the ‘poor’ threshold, the Commission for Air Quality Management decided to revoke GRAP measures , which had imposed restrictions on construction activities, vehicular movement, and industrial operations during peak pollution months. The rollback signals a temporary return to normalcy for residents and businesses.

However, experts caution that the relief may be fragile and short-lived . As temperatures rise, ground-level ozone has begun emerging as a key pollutant , particularly during sunny afternoon hours. This marks a seasonal transition in Delhi’s pollution profile, where winter particulate matter gives way to summer ozone formation driven by sunlight and vehicular emissions.

Early trends already indicate fluctuations in AQI levels , with readings inching upward in several areas, suggesting that the gains from rainfall may not sustain without continued favourable weather. Forecasts indicate that air quality is likely to remain in the ‘moderate’ category over the next few days, supported by intermittent rain and gusty winds , though a gradual deterioration cannot be ruled out.

On the weather front, Delhi recorded a maximum temperature of 32.2 degrees Celsius, 3.3 degrees above normal, reflecting the onset of warmer conditions. Minimum temperatures also remained above average across most stations, further signalling the seasonal transition. While the cleanest air in six months and the lifting of GRAP restrictions offer a welcome reprieve, officials underline that Delhi’s air quality remains highly weather-dependent and structurally vulnerable , requiring sustained emission control measures beyond seasonal improvements.