Southwest Monsoon Ends With 12% Deficit in Lowest Rainfall Since 2015

India's southwest monsoon ended with 759.4 mm of rain, which is 12.6% below the normal rainfall of 868.6 mm, according to the India Meteorological Department. At 87% of the Long Period Average, this marks the lowest rainfall recorded during the monsoon season since 2015. The east and northeast region recorded 1,017.1 mm of rainfall, marking its driest monsoon since systematic records started in 1901.

Regional Impact

The largest drops in rainfall happened in east and northeast India at 25.6% below normal, where IMD director general M. Mohapatra noted a clear trend of diminishing rainfall in recent years. The southern peninsula saw rainfall 24.3% below normal at 542 mm, making it the fourth lowest monsoon rainfall for the region since 1901. Northwest India ended 5.9% below normal, while central India stood at 2.6% below normal. Punjab, Arunachal Pradesh, and the Assam & Meghalaya subdivisions stayed rain-deficient in every month from June to September. Nationally, 17 of 36 subdivisions saw deficient rainfall, covering 42% of the country's land area, while 18 were normal and one had excess rain. Out of 741 districts assessed, 282 were deficient and 34 were large deficient.

Forecast and Temperatures

The weak monsoon followed forecasts of a strong El Nino by global weather agencies and the IMD. June recorded 65% of normal rainfall, July ended with 1% more than expected due to central India rains, August came in at 84% of the LPA, and September finished at 92.4%. Mr. Mohapatra stated that predictions matched conditions in many regions except parts of northwest and adjoining central India. The monsoon is now withdrawing and will likely exit completely within the first weeks of October. With El Nino still gaining strength, October rainfall is likely to be below 85% of the LPA, with most regions getting below-normal rain except parts of northwest India, southern peninsular India, and isolated parts of the east. Maximum and minimum temperatures are likely to be above normal across most of the country, though Punjab, Haryana and northern states may see good rain from western disturbances to help the winter crop.

Context

The southwest monsoon is crucial for India's agriculture, supplying the bulk of the water needed for crops and replenishing reservoirs across the country. El Nino events, which involve the warming of ocean water in the central and eastern Pacific Ocean, frequently disrupt normal weather patterns and lead to drier conditions across parts of South Asia. Understanding these seasonal shifts helps farmers and planners manage water resources and prepare for changing weather conditions.