India's southwest monsoon ended the June-to-September 2026 season with 759.4 millimetres of rain, compared with a long-period average of 868.6mm. That is a deficit of about 12.6%, placing the all-India season in the India Meteorological Department's deficient range.
The national total is important, but it does not describe every state's experience. Central India finished in the normal range, while east and northeast India and the southern peninsula recorded much larger shortfalls. Local floods can also occur during a nationally deficient season because rainfall distribution matters as much as the final total.
The final monsoon numbers
IMD's September 30 release lists the all-India rainfall at roughly 87% of the long-period average. Published summaries describe it as the weakest monsoon since 2015 and the fourth-lowest seasonal rainfall since 2001.
Regional figures reported from the IMD assessment include a deficit of about 5.8% in northwest India, 25.6% in east and northeast India and 24.4% in south peninsular India. Central India's cumulative total remained within the normal band.
These percentages are broad regional aggregates. A district can end above normal even when its wider region is deficient, and rainfall arriving in a few intense episodes may not support crops or reservoirs in the same way as well-distributed rain.
Why a 12.6% deficit matters
The monsoon supports rain-fed agriculture, reservoir recharge, hydropower and urban water supplies. A weak season can increase irrigation demand and make winter-crop planning more sensitive to stored water and post-monsoon rain.
The impact is not automatic or uniform. Crop outcomes depend on sowing dates, soil moisture, irrigation access, temperature and the timing of rainfall. Reservoir levels also reflect water carried over from earlier seasons and catchment-specific rain, not just the national percentage.
Households should therefore use state and district advisories rather than drawing direct conclusions from the India-wide figure. Farmers can follow agriculture departments and local agrometeorological bulletins for crop-specific guidance.
What caused the weak season?
IMD's seasonal assessment links the broader pattern to atmospheric and ocean conditions, including El Niño. That does not mean El Niño mechanically produces the same result in every Indian region. The Indian Ocean, monsoon depressions, intra-seasonal breaks and local weather systems can modify the outcome.
Weather attribution should also distinguish between a seasonal driver and a single extreme event. One depression can cause flooding in a state without reversing the national deficit.
What to watch after the monsoon
The next focus is the post-monsoon season and October rainfall. IMD publishes separate seasonal outlooks and shorter-range forecasts. Those updates will matter for soil moisture, reservoir inflows and rabi sowing.
Users should also monitor the Central Water Commission's reservoir bulletins and state agriculture advisories. A headline about the national deficit is the starting point for planning, not a complete local forecast.
Questions readers are asking
Was every part of India 12.6% below normal? No. That is the national aggregate. Regional and district totals varied widely.
Can flooding happen in a deficient monsoon? Yes. Short periods of extreme rain can cause floods even when the full-season total finishes below average.
Does a weak monsoon guarantee crop losses? No. Irrigation, crop choice, rainfall timing, soil moisture and post-monsoon weather all influence output.
Where should local users check conditions? Use IMD district forecasts, state disaster authorities and agriculture advisories rather than applying the national number directly.
The end of the southwest monsoon accounting period also does not mean rain stops nationwide. Northeast monsoon conditions become important for parts of southern India, and individual systems can still produce heavy rainfall in October.
Updated October 1, 2026, 12:27 IST. Rainfall totals are based on IMD's end-of-season release and may receive quality-control revisions.
