The monthly average PM 2.5 concentration was recorded to be the highest in November at all monitoring stations, except ITO and Dilshad Garden.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/new-delhi-no-%E2%80%98good%E2%80%99-air-quality-day-throughout-winter-says-report
[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-pollution
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/pm-25
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi-pollution-control-committee-dpcc
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/centre-science-and-environment-cse
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/industrial-pollution
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-quality-standards