Southwest Monsoon Rainfall Forecast

Southwest Monsoon Rainfall Forecast
  • Context:

  • The India Meteorological Department (IMD) has issued its first long-range forecast for 2026, issuing a warning that the Southwest Monsoon (SWM) will be "below normal" for the first time in 11 years.

  • This raises significant concerns for India's agrarian economy just ahead of the crucial Kharif sowing season

  • Forecast Details:

  • Rainfall Deficit:

  • During the core monsoon months of June to September, India is projected to receive only 92% of the Long Period Average (LPA) of 87 cm of rainfall.

  • A monsoon is officially categorized as "below normal" when the predicted rainfall for the season falls between 90-95% of the LPA.

  • The Primary Driver:

  • The primary reason for this suppressed rainfall is the anticipated development of El Niño conditions—the periodic warming of the Central Equatorial Pacific.

  • Currently, "weak" La Niña-like conditions are transitioning to neutral, with El Niño expected to take full effect by the second half of the monsoon.

  • Historically, El Niño has depressed India's monsoon rainfall nine times in its 16 occurrences since 1960.

  • Counter-Balancing Climate Factors:

  • Climate scientists note that certain phenomena could partially offset the negative impacts of El Niño:

  • Positive Indian Ocean Dipole (IOD):

  • An oscillation of sea-surface temperatures between the western (near Africa) and eastern (near Indonesia) tropical Indian Ocean, which generally brings more rain to India.

  • Reduced Snow Cover:

  • The extent of northern hemisphere snow cover from January to March 2026 was slightly below normal, a condition favorable for the SWM.

  • Global Warming:

  • Excess moisture accumulated due to global warming since 2000 has been known to cause localized heavy rainfall, such as recent observations in Rajasthan.

  • Agricultural Impact:

  • This forecast presents a "double whammy" for the approximately 60% of Indian farmers who are completely dependent on rainfed agriculture.

  • They are already reeling from pre-monsoon hailstorms and flooding and must now navigate this rainfall deficit alongside anticipated fertilizer supply disruptions linked to the ongoing West Asia conflict.