Delhi Breathes Easy: August Marks Cleanest Air in Years Thanks to Monsoon Magic

Delhi, a city often synonymous with challenging air quality, breathed a collective sigh of relief in August 2023, recording its cleanest air for the month since 2020. This remarkable turnaround is largely attributed to an extended and generous spell of monsoon rainfall, which meticulously washed away pollutants and bestowed upon the capital a rare period of pristine air.

Throughout August, the city's Air Quality Index (AQI) remained steadfastly in the 'good' to 'satisfactory' categories, a significant departure from the typically fluctuating and often concerning readings. Out of the 31 days, a staggering 18 saw the AQI classified as 'good,' while the remaining 13 days fell into the 'satisfactory' bracket. Crucially, not a single day registered 'moderate,' 'poor,' 'very poor,' or 'severe' air quality, a testament to the profound impact of the continuous downpours.

This August's average AQI stood at an impressive 94.6, comfortably within the 'satisfactory' range. This marks a notable improvement when compared to previous years' August statistics. In August 2022, Delhi experienced seven 'moderate' air quality days with an average AQI of 100. Even more starkly, August 2021 saw ten 'moderate' days and one 'poor' day, pushing the average AQI to 102. The current year's performance even nudges slightly better than August 2020, which recorded an average AQI of 94, placing 2023 as the cleanest in this four-year span.

The reduction in primary particulate matter was equally impressive. Levels of PM2.5, fine particulate matter small enough to enter the lungs, remained below the national ambient air quality standard of 60 µg/m³ for 29 out of 31 days. Similarly, PM10, larger inhalable particles, stayed below its standard of 100 µg/m³ for 25 days. These consistently low levels underscore the efficacy of the extensive rainfall in cleansing the atmospheric burden.

Scientists and experts concur on the primary cause. Data from the System of Air Quality and Weather Forecasting and Research (SAFAR) and the Central Pollution Control Board (CPCB) consistently points to the continuous and widespread rainfall as the dominant factor. The precipitation acted as a natural scrubber, effectively depositing airborne pollutants back to the ground and preventing their accumulation.

While August's clean air provides a welcome respite, the city's environmental watchdogs remain cautiously optimistic. As the monsoon season begins its retreat and the cooler, drier months approach, the familiar challenges of air pollution are expected to re-emerge. Specifically, the onset of crop stubble burning in neighbouring states, combined with calmer wind conditions, typically leads to a significant deterioration of air quality in September and October. Therefore, while we celebrate this momentary triumph, the long-term battle for sustainable clean air in Delhi continues, underscoring the need for consistent, year-round mitigation strategies.