• PM2.5/PM10 ratio characteristics over India using multi-site and multi-year data.
• Suppressed PM2.5/PM10 ratio variations compared to that observed in PM concentrations.
• MERRA-2 derived PM2.5/PM10 ratio found to be overestimating during colder months.
• Weak relationship between the PM2.5/PM10 ratio and meteorological parameters.
(*B. Spandana, S. Srinivasa Rao, and Adithi R. Upadhya are the other authors of this paper.)