The role of the Arabian Sea (AS) warming on the Indian summer monsoon rainfall is investigated using regional climate model‐Regional Climate Model version 4.7 of International Centre for Theoretical Physics. The model realistically simulates the rainfall, temperature, low‐level winds and vertically integrated moisture flux over the Indian region during the years 2006–2015. It is found that the AS warming decreases the rainfall over most parts of the India, which is mainly due to decrease in the convective precipitation over these regions. The AS warming reduces the magnitude of westerly winds in the southern Bay of Bengal and AS; enhances the moisture convergence over the AS; and causes the prohibition of the moisture‐laden winds from the AS to reach to the Indian land regions resulting into decreased precipitation. The effect of anti‐cyclonic circulation produced over the central India as a result of the AS warming is to further reduce the monsoon rainfall. It is also shown that the AS warming increases the extreme rainfall over most parts of India.

Using long daily rainfall (113 years) data, clear evidence of modulation of the statistics of subseasonal active and break spells of the Indian summer monsoon rainfall (ISMR) by the El Niño–Southern Oscillation (ENSO) is unraveled. We show that during the El Niño (La Nina) years, the frequency of longer break (active) spells and shorter active (break) spells increases substantially, while the frequency of shorter breaks (active) and longer active (break) spells decreases compared to ENSO neutral years. It is shown that the large‐scale teleconnection through which ENSO weakens (strengthens) the ISMR through shortening (lengthening) of the length of rainy season (LRS) also creates a background for modulation of the statistics of subseasonal spells leading to a further reduction (increase) in the ISMR during El Niño (La Niña) years. Our findings indicate that the “statistics of subseasonal spells” is predictable, brightening the prospect of seasonal prediction of the ISMR.