ExplainedClimate
Why the wettest corner of India had its driest monsoon on record
East and Northeast India got a quarter less rain than normal this year, the lowest since 1901, and Meghalaya ended 60% short. How the rain-bearing systems missed the region, what El Niño has to do with it, and what a dry winter could mean.
The short answer
The monsoon's rain over East and Northeast India comes mostly from low-pressure systems that form over the Bay of Bengal. This year none did: the 14 systems of the season were remnants of West Pacific storms, and they tracked elsewhere. A developing El Niño, the warming of the Pacific that tends to weaken the Indian monsoon, made things worse. The region got 1,017.1 mm against a normal of 1,367.3 mm, and with El Niño expected to strengthen, the outlook for October to December is also dry.
How dry was it?
The driest in 125 years of records.
Between June and September, East and Northeast India received 1,017.1 mm of rain, against a normal of 1,367.3 mm. That is 25.6% short, and below the previous record low of 1,065.7 mm in 2013. Meghalaya, home to some of the wettest places on earth, finished 60% short. Manipur was 46% below normal, Arunachal Pradesh 44%, Bihar 32% and Assam 28%.
India as a whole got 759.4 mm, 87% of its long-period average and its weakest monsoon since 2015, according to the India Meteorological Department (IMD). Seventeen of the country’s 36 meteorological subdivisions were deficient.
Where does the region’s rain normally come from?
Mostly from the Bay of Bengal.
During a normal monsoon, a string of low-pressure areas and depressions forms over the warm waters of the Bay. They draw in moist air from the sea and carry it inland, dumping heavy rain over Odisha, Bengal, Bihar and the hills of the Northeast, which wring the moisture out as the air rises.
This year that engine stalled. K J Ramesh, a former Director General of IMD, said the season produced 14 low-pressure systems with 77 low-pressure days between them, a fairly normal count. But not one formed over the Bay of Bengal. All were the remnants of storms born in the West Pacific, and they did not bring the region its usual rain.
What does El Niño have to do with it?
It tilts the odds towards a weak monsoon.
El Niño is the periodic warming of the surface of the central and eastern equatorial Pacific. It shifts the pattern of rising and sinking air across the tropics, and in most El Niño years the Indian monsoon is weaker than normal. This year an El Niño began building during the season and is still strengthening.
Roxy Mathew Koll of the Indian Institute of Tropical Meteorology has pointed out that climate change does not cause El Niño, but raises background temperatures, which makes its effects more intense. Local changes such as deforestation can amplify them further.
Is this a one-off?
No. It is the latest in a long run of weak years.
East and Northeast India have had below-normal monsoon rain in nine of the last ten years, the only exception being 2020. The deficit was 14% in 2024 and 20% in 2025. Mahesh Palawat of Skymet Weather says low-pressure systems are now lingering over land for longer while holding their strength, “partly due to a sustained supply of moisture”, which changes where the rain falls.
Who feels it?
Farmers first. Rice, the main kharif crop in the region, needs standing water. Nationally, the area under rice was 15.56 lakh hectares lower by 5 October than a year earlier. G V Ramanjaneyulu of the Centre for Sustainable Agriculture says farmers seem to be switching to less thirsty crops, and warns that weak groundwater recharge will push up dependence on irrigation in the coming months.
The dry weather also came with heat. August 2026 was India’s hottest August since 1901.
What comes next?
Probably more dry weather.
IMD expects October rain to be below normal, under 85% of the long-period average, and most of the country to get below-normal rain from October to December. Forecasts give El Niño an 83% chance of becoming the strongest since 1950 over those months and a near-certain chance of lasting until February 2027. Ramesh has warned that summer heat could arrive as early as February.
Aarti Khosla, director of Climate Trends, which analysed the IMD data, says states need to shift “from response to preparedness”: early warnings, water plans and heat action plans in place before the next hot season, not after it starts.