Air pollution is one of the biggest concerns faced by developing countries like India and the world at large. The capital of India, Delhi and the National Capital Region (NCR), sees life threatening air pollution levels. We present a new Particulate Matter (PM) dataset for Delhi-NCR, which contains PM data recorded over three months from November 2020 to January 2021 over an area spanning 559 square Kms. The data has been collected using vehicle-mounted IoT sensors, designed and built in IITD incubated startup Aerogram. The deployment is in collaboration with the Delhi Integrated Multi-Modal Transit System (DIMTS) buses with permission from the Delhi Ministry of Transport. The 13 bus dataset has been compared with the data over the same period obtained from the pre-existing static sensors, maintained by Central Pollution Control Board (CPCB) and Delhi Pollution Control Board (DPCC), which the buses pass by. The correlations between the static sensors and our mobile sensors have been found to be excellent. Hence we release this dataset, though this has been a pilot deployment mainly to find device and bus anomalies (relatively few), for a larger scale deployment in 2021-22. This website will be updated as new data gets collected and cleaned, as we scale up our deployment to more buses and include more sensors in addition to the current PM sensors (e.g. SOx, NOx, COx). We are funded by DST-SERB under IMPRINT-II grant scheme (2019-2022) for this project.