According to the Central Pollution Control Board (CPCB) data, the overall Air Quality Index (AQI) in the city was 338.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/delhi%E2%80%99s-pollution-level-falls-year%E2%80%99s-lowest-after-rainfall
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/indian-express-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-quality-index-aqi
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/central-pollution-control-board-cpcb
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/pm-25
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-quality-standards
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rainfall