India recorded a sharp 40% rainfall deficit during June 2026 as the southwest monsoon struggled to gain momentum, with meteorologists attributing the shortfall to a strengthening El Niño, an unfavourable Madden-Julian Oscillation (MJO), and the absence of low pressure systems over the North Indian Ocean.
According to the India Meteorological Department (IMD), while the monsoon has advanced across most parts of the country, rainfall has remained significantly below normal in nearly all regions. Central India has been the worst affected, recording a 50% rainfall deficit during June, followed by east and northeast India with a 40% shortfall. Southern peninsular India received 27% less rainfall than normal, while northwest India, where the monsoon is still progressing, recorded 31% below normal rainfall.
More than three fourths of India’s districts have experienced deficient rainfall. As of June 29, nearly 76% of districts had received deficient, largely deficient or no rainfall. Meghalaya recorded the highest rainfall deficit among states where the monsoon had already arrived, receiving 76% less rain than normal. Manipur followed with a 72% deficit, while Jharkhand and Chhattisgarh each recorded 66% below normal rainfall. Fifteen other states and Union Territories also reported deficient rainfall during the month.
El Nino and weak atmospheric conditions slow monsoon
Scientists say the developing El Niño has been a major factor behind the delayed and weakened monsoon. The US National Oceanic and Atmospheric Administration (NOAA) officially declared the onset of El Niño on June 11, forecasting that it could persist into early 2027. El Niño typically suppresses monsoon rainfall over India by altering atmospheric circulation across the Pacific Ocean.
Climate experts, however, note that El Nino is not acting alone. They point to the unfavourable Madden Julian Oscillation, weak monsoon circulation and the absence of low pressure systems over the Bay of Bengal and the Arabian Sea as additional reasons for the rainfall deficit. These conditions have prevented the formation of Monsoon Intra seasonal Oscillations (MISO), which normally generate rain bearing low pressure systems during the monsoon season.
Experts also say changing global warming patterns and atmospheric interactions, including the influence of the Meiyu Baiu weather system over East Asia, are contributing to delays in monsoon onset and uneven rainfall distribution across India.
Low pressure systems may improve rainfall in July
Despite the weak start meteorologists remain cautiously optimistic about the coming weeks. The IMD has indicated that an upper air cyclonic circulation over the north Bay of Bengal is likely to develop into a low pressure area around July 3. Additional low pressure systems over central India could strengthen the monsoon trough and enhance rainfall across many parts of the country.
Weather experts believe these evolving systems may help revive monsoon activity during early July, reducing the rainfall deficit if conditions remain favourable. However, they caution that the progress of the season will continue to depend on the behaviour of El Nino and the development of rain bearing weather systems over the Indian Ocean region.