Delhi’s air quality this October has been the most polluted since 2020, with current data indicating minimal improvement in the foreseeable future. The average Air Quality Index (AQI) for the first 19 days of this month stands at 181.7, surpassing the averages of 2022 and 2021, though still below 2020’s 226.1.
Forecasts predict the AQI to decline into the poor category by Friday, likely persisting for the subsequent six days. IMD officials attribute this to decreasing wind speeds, dipping from 6-8 km/hour to 4-8 km/hour by the weekend. Although a slight rise in wind speed is anticipated on Sunday, air quality is projected to remain poor.
The notably better AQI in 2022, the best in six years, was credited to a late monsoon retreat coupled with consistent post-monsoon rainfall caused by western disturbances (WD). Similarly, 2021’s improved AQI was due to an increased number of rainy days.
In contrast, 2022 saw only one WD affect the city, resulting in a single day of rainfall. While the city experienced a brief improvement in AQI over the past three days due to rain and robust winds, the effect is transient, with only a slight chance of light rain forecasted for Sunday.
However, conditions currently don’t suggest the AQI deteriorating beyond the poor range. For pollutant dispersion to be unfavourable, a ventilation index below 6000 m2/s and wind speeds under 10 kmph are required, neither of which are anticipated in the upcoming week.
