The study intends to support the Delhi government, the Central Pollution Control Board (CPCB), and the Delhi Pollution Control Committee (DPCC) in identifying priority areas of interventions needed in controlling air pollution in Delhi during the winter season of 2021. It establishes the primary drivers of Delhi's winter air pollution during the different phases of the season. It considers meteorological parameters, source activity levels, and its contributions to investigate how winter 2020 was, if at all, different in the pandemic circumstances compared to the previous years.