The India Meteorological Department (IMD) has issued its initial long-range forecast for the 2026 southwest monsoon, indicating a likelihood of below-normal rainfall across the country. This forecast, released in April, projects rainfall at approximately 92% of the Long Period Average (LPA) for the crucial June-September season.
The southwest monsoon is vital for India's economy, particularly its vast agricultural sector. As many regions grapple with intense summer heat, attention is shifting to this weather system, which supplies nearly 70% of the nation's annual rainfall and significantly impacts farming, water resources, and power generation.
Monsoon Arrival Dates and Early Onset Hints
According to the IMD, the southwest monsoon is anticipated to make landfall on the Kerala coast around its usual onset date in early June. However, some international weather models, including the European Centre for Medium-Range Weather Forecasts (ECMWF), suggest a potentially earlier arrival, possibly in the last week of May.
IMD Director General Mrutyunjay Mohapatra noted that monsoon rains are expected to commence over the Andaman and Nicobar Islands between May 14 and May 20. This serves as an important precursor to the monsoon's progression towards mainland India.
Typical Monsoon Progression
Under normal circumstances, the southwest monsoon follows a predictable path across India:
- Kerala: Around June 1
- Mumbai: Around June 10
- Central India: Mid-June
- Delhi-NCR: Around June 27 to June 30
- Entire Country: By approximately July 15
The IMD explains that the monsoon advances northward in distinct phases or “surges,” influenced by factors such as sea surface temperatures, wind patterns, and low-pressure systems developing over the Bay of Bengal and Arabian Sea.
El Niño Threatens Rainfall Distribution
While neutral conditions currently prevail in the Pacific Ocean, climate models indicate a significant possibility of El Niño developing by July. The emergence of El Niño conditions later in the monsoon season could adversely affect rainfall distribution across India, exacerbating the impact of a below-normal forecast.
Despite the overall seasonal outlook, the IMD anticipates normal to above-normal pre-monsoon rainfall activity across many regions in May. This could offer some temporary relief from the ongoing heatwave conditions.
Economic Implications for India
The performance of the southwest monsoon is critical for India's economic stability. A large portion of the country's kharif (summer) crop cultivation relies heavily on timely and well-distributed rainfall. Beyond agriculture, monsoon performance directly influences reservoir levels, hydropower generation, and rural consumption patterns, underscoring its profound impact on the nation's well-being.