Recent satellite imagery shows extensive cloud cover and the India Meteorological Department (IMD) reports very heavy rainfall in several subdivisions across India. However, despite these widespread showers, the nation's overall monsoon rainfall stands at 21% below the expected level for this point in the season.
Understanding the Monsoon Deficit Calculation
The apparent contradiction between heavy localized rains and a national deficit lies in how monsoon shortfalls are calculated. The IMD defines a deficit by comparing actual rainfall against the Long Period Average (LPA), which represents the typical rainfall received over several decades during the June-September monsoon season. A shortfall between 20% and 59% is officially classified as "deficient." With India currently 21% below the expected mark, the monsoon has entered this category.
India's LPA for the entire four-month monsoon season is 868.6 mm. At the current stage, the country is approximately 76 mm below this expected cumulative total.
The Path to Monsoon Recovery
Closing the existing rainfall gap requires significantly above-normal rainfall throughout August and September. However, the deficit percentage can decrease even if the remaining period only receives normal rainfall. This is because the percentage deficit is calculated against the expected rainfall for the entire season, and as the season progresses, this normal rainfall benchmark continues to increase.
If the rest of the season sees normal rainfall, India could still reach around 792 mm by September, approximately 91% of the LPA. This scenario would reduce the current 21% deficit to about 9% without requiring extraordinary rainfall.
August: A Critical Month for the Monsoon
Monsoon rainfall is not evenly distributed throughout the season. Large parts of India typically receive substantial rainfall from low-pressure systems that form over the Bay of Bengal and traverse the country. These systems can deliver intense rainfall across multiple states within a few days, significantly impacting national rainfall averages.
August is considered a pivotal month because these rain-bearing systems are more frequent during this period, offering the monsoon its best opportunity to compensate for lost ground.
El Niño's Influence and Agricultural Impact
This year's broader weather patterns are also influenced by El Niño, a phenomenon involving the warming of parts of the Pacific Ocean, which can alter global circulation patterns and affect India's monsoon. The IMD has incorporated these conditions into its forecast, projecting the 2026 monsoon rainfall at approximately 90% of the LPA, placing it in the below-normal category.
It's important to note that national rainfall figures don't always reflect the full picture. Nearly half of India's cultivated land relies solely on rainfall for irrigation, meaning heavy downpours in one region may not alleviate drought conditions in agricultural areas elsewhere.