Generally, during the south-west monsoon season, several severe/ extreme weather systems form over India, leading to heavy rainfall. Such heavy rainfall result in floods for wider region of northern India, and, which, finally, causes loss of agriculture, human and animal’s life, outbreak of diseases/ epidemics, and thus affecting national economy. An attempt has therefore, been made to analyze the disastrous events that occurred in the summer monsoon months over different states in India for the period 1981-2000. The analyses included the raining event which were active, but, caused due to- or without the monsoonal-systems that were formed in north Indian Ocean. Results showed that West Bengal was the mostly affected state during monsoon season, where both, local as well as monsoonal systems were equally responsible for heavy rainfall/ flood events. The local atmospheric phenomenon affected highly to Uttar Pradesh, West Bengal, Gujarat, and Maharashtra, whereas for systems that were associated with the north Indian Ocean and Bay of Bengal, the states of West Bengal and Orissa were the mostly affected states. From the study, it may be concluded that all the heavy rainfall related disastrous weather events formed over different states in India was not only due to systems developed over Oceans, rather, local atmospheric phenomena had equally important contributor of similar affects, particularly for northern and western India.