...Average April AQI in capital worst since 2022

New Delhi: Apart from high temperatures, Delhiites experienced the most polluted April in three years. The average Air Quality Index in April was 213 against 182 last year and 180 in 2023. April 2022 with average AQI of 255 last exceeded this year's mark. There were 20 'poor' air days this April compared with 13 in 2024 and 2023. However, April 2022 had seen 29 ‘poor' days and one ‘very poor' day.
So far this month, there have been nine 'moderate' air days and 20 'poor' days, with a streak of five consecutive ‘poor' days from April 6 to 10. Rain and winds on the evening of April 10 improved the air quality. The city is seeing another ‘poor' streak of nine days since April 21. There has been no ‘good' or ‘satisfactory' air day this April.

Ozone and dust were among the main sources of pollution in April, with ozone and PM10 remaining the lead pollutants on most days. An official said the month was mostly dry, so there was no rain to wash out the pollutants.
Dipankar Saha, former head of Central Pollution Control Board's air laboratory, who analysed the AQI data of April from 2016 to 2025, said the overall air quality in the month was between ‘moderate' and ‘poor'.
Anumita Roychowdhury, executive director, research and advocacy, Centre for Science and Environment, had earlier said that the pollution was the result of the intensification of summer conditions. "This necessitates upscaled and stringent implementation of priority measures to control pollution generated by vehicles, transport, waste and households. Ensuring on-ground change is critical for clean air," said Roychowdhury.
Stage I of Graded Response Action Plan for ‘poor' air has been in force since April 2. The measures under Stage I are preventative and focus on the enforcement of existing curb guidelines. According to the Air Quality Early Warning System, the forecasting body under the Union ministry of earth sciences, the air quality of the city is likely to stay in the ‘moderate' from April 30 to May 2.
CPCB classifies AQI between 0-50 as ‘good', between 51 and 100 as ‘satisfactory', between 101 and 200 as ‘moderate', between 201 and 300 as ‘poor', between 301 and 400 as ‘very poor', and over 400 as ‘severe'.
Sunil Dahiya, founder and lead analyst, Envirocatalysts, said, "Consistent poor air quality beyond winter months shows that it's not just factors beyond human control, such as meteorology, which make Delhi's air unbreathable. Polluting anthropogenic activities and resultant emissions are the primary reasons. Only a systematic approach centred on emission load reduction and a larger air shed can provide breathable air in the region."