<p>The summer monsoon is a major weather phenomenon and has a significant socio-economic influence on India. In this context, understanding the long-term trend and the dynamics of extreme rainfall events (EREs), especially over the arid and semiarid regions like northwest India, remains limited. In this study, we delve into not only understanding the long-term trend and how they evolve in a warming climate but also elucidate the complex driving mechanisms of these events over the arid and semiarid regions of northwest India. Using high-resolution long-term rainfall datasets, EREs are classified into three major categories based on their spatial extent: widespread extreme rainfall events (WEREs), localized extreme rainfall events (LEREs), and EREs (comprising both WEREs and LEREs). Trend analysis spanning over a century indicates a significant upward trend in the frequency of WEREs. Additionally, the contribution of EREs to seasonal rainfall shows a notable increase, especially over western Gujarat. The composite analysis reveals distinct patterns in WEREs and LEREs, showcasing the evolution of rainfall and anomalous low pressure over the region. Results suggest strong vertical velocity and middle-level tropospheric heating are the key drivers of these EREs. In addition, high values of potential vorticity and moist static energy in the mid-level are key features of these systems, with snow hydrometeor being the major contributor to rainfall. This study's findings underscore the growing concern about EREs affecting the arid and semiarid region, which is already vulnerable due to their limited vegetation and scarce water resources.</p>