Delhi: In the period spanning from January to October 2023, Delhi has witnessed a consistent trend of improved air quality, with daily average Air Quality Index (AQI) numbers painting an optimistic picture. The city’s daily average air quality during this 10-month duration has reached its best index, surpassing figures from the last six years (except for the COVID-impacted year of 2020).
The daily average AQI for Delhi during the aforementioned period in the current year stands at 172. This marks a notable improvement when compared to the AQI levels of 187 in 2022, 179 in 2021, 156 in 2020, 193 in 2019, and 201 in 2018, during the corresponding months.
The levels of AQI are significantly influenced by factors such as rainfall, precipitation, and wind speed, all of which play crucial roles in dispersing pollutants and emissions. Effective dispersal is vital for maintaining good air quality, even with controls in place to reduce emissions from primary sources in the region.
In October 2023, Delhi experienced minimal rainfall, with only 5.4 mm of precipitation, a sharp contrast to the 6-7 days of rainfall in October 2022 and 2021, resulting in cumulative rainfall of approximately 129 mm and 123 mm, respectively, for those months.
Furthermore, the average wind speed during October 2023 was notably slower, and periods of absolute calm were observed during the month. Despite the lack of significant rainfall and low wind speeds, the daily average AQI for October 2023 reached 219, only slightly higher than the daily average AQI of 210 in October 2022.
Another encouraging statistic is that Delhi recorded the highest number of days (206) with “Good” to “Moderate” air quality (Daily Average AQI < 200) during January to October 2023, in comparison to the same period in previous years (except for the COVID-impacted 2020).
In contrast, the number of “Good” to “Moderate” air quality days in previous years was 160 in 2022, 197 in 2021, 175 in 2019, and 157 in 2018.
Moreover, 2023 has seen a significant reduction in daily average PM2.5 and PM10 concentrations compared to the past six years. The daily average PM2.5 concentration during January to October 2023 was approximately 75 µg/m³, compared to a range of 81-95 µg/m³ during the same period from 2017 to 2022 (except for the COVID-impacted 2020).
Similarly, the daily average PM10 concentration in Delhi in 2023 was about 173 µg/m³, significantly lower than the range of 182-220 µg/m³ recorded during the corresponding periods from 2017 to 2022 (except for the COVID-impacted 2020).
In light of the unfavorable meteorological and climatic conditions, measures under GRAP Stage-II were proactively implemented on October 21, 2023, aiming to intensify preventive measures and delay the invocation of Stage-III of the GRAP as much as possible. It’s worth noting that in previous years, Stage-III of the GRAP was invoked in the last week of October, a situation not witnessed in 2023.
The Commission reiterates its call to all stakeholders to effectively implement directions and guidelines related to air pollution control, especially those outlined in the GRAP schedule. Citizens are encouraged to follow the Citizen Charter in the collective effort to improve air quality.