India will enter the 2026 monsoon season under the shadow of one of the most worrying climate signals in recent years as a potentially historic El Niño event forms in the Pacific Ocean and threatens to disrupt rainfall in large parts of the country from August.
The India Meteorological Department (IMD) released its first long-range forecast for 2026 on April 13, warning that the southwest monsoon, which lasts from June to September and serves as India’s primary rainy season, is likely to bring subnormal or deficient rainfall this year.
The driver of this forecast is a rapidly strengthening El Niño event, which climate scientists say could rival the catastrophic cycles of 1997 and 2015.
What is El Niño and why does it threaten the Indian monsoon?
El Niño is a periodic warming of the central Pacific Ocean that disrupts weather systems around the world. For India, its implications are particularly significant. When El Niño strengthens, it tends to weaken the monsoon winds that carry rainfall across the subcontinent, suppressing rainfall in the northern, central and western regions, while paradoxically triggering excessive rainfall along parts of the southern and eastern coasts.
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The Pacific has already begun to show clear signs of warming. Sea surface temperatures in key monitoring areas are currently about 0.5 degrees Celsius above the long-term average, a level scientists consider an early but significant indicator of El Niño conditions.
Meteorologists have noted that the transition from the previous La Niña cycle is occurring more quickly than usual, a pattern that does not occur every year and which experts say may be the first stage of a stronger event.
What the IMD forecast actually says about 2026 monsoon rain
The IMD predicts that monsoon rainfall this year is likely to reach 92 percent of the long-term average, placing it in the below-normal category. The long-term average, calculated on the basis of data from 1971 to 2020, is about 870 millimeters between June and September.
Even more remarkably, the probability of a deficient season, defined as precipitation falling below 90 percent of the long-term average, is 35 percent. That number is more than double the historical probability of 16 percent, underscoring the degree to which this year’s outlook deviates from the typical monsoon season.
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Both the IMD and Skymet, India’s leading private weather forecasting agency, suggest that the first half of the monsoon, especially June, may remain relatively stable. More severe deterioration is expected to come in August and September, when El Niño’s influence on atmospheric circulation will be felt most strongly.
How strong could this El Niño be?
Scientists use the Niño3.4 index, a measurement tool developed and monitored by the US National Oceanic and Atmospheric Administration, to track sea surface temperature anomalies in a defined area of the Pacific and classify the intensity of El Niño events.
Under this classification system, an event in which temperatures exceed 1.5 degrees Celsius above the historical average is designated as strong, while anything above 2 degrees Celsius qualifies as a super El Niño.
Some current forecast models predict a temperature increase of more than 2 degrees Celsius by the end of the year, with some scenarios showing anomalies in excess of 2.5 degrees Celsius.
Read also | 2026 could see a super El Nino and record global temperatures
This would make the event one of the strongest in history. Forecasting agencies including the US National Oceanic and Atmospheric Administration and the Australian Bureau of Meteorology are closely monitoring the situation and are seeing increasing evidence that conditions may strengthen further by the end of 2026.
Which Indian cities and regions face the greatest risk?
The geographic impact of a strong El Niño across India is not uniform, and the differences between affected regions can be dramatic.
According to an India Today report, India’s northern, western and central regions face the highest risk of drought, with prolonged drought and agricultural losses among the primary concerns. Punjab, Haryana and Rajasthan are considered particularly vulnerable in August and September.
The main monsoon belt across central and western India is expected to receive deficient rainfall, with specific areas of Madhya Pradesh including Indore, Ujjain, Gwalior, Chambal, Jabalpur, Rewa, Shahdol, Sagar and Narmadapuram forecast to receive below normal rainfall.
There is little prospect of monsoon relief for Delhi-NCR, which is already experiencing worsening extreme heat. Drier and warmer conditions are expected to continue through the end of the season.
Read also | El Nino ends, La Nina expected to bring relief: Australian Met Dept
Chennai and coastal Tamil Nadu face the opposite problem. Rather than drought, these areas are at increased risk of excessive rainfall and flooding, a pattern consistent with previous El Niño years when the city suffered heavy flooding.
Regions that will be largely spared significant deficits include Ladakh, parts of Rajasthan, the Northeast and the northern southern peninsula including Telangana.
What El Niño 2015 and 2023 did to India
The implications of a strong El Niño for India are not hypothetical. India has experienced comparable events within living memory, and the damage they caused provides a sobering baseline for what 2026 could bring.
During the last comparable super El Niño in 2015 to 2016, actual monsoon rainfall was only 86 percent of the long-term average, triggering widespread drought across the country.
The Marathwada region of Maharashtra experienced a 40 percent rainfall deficit that year, destroying crops and deepening the plight of farmers in one of India’s most agriculturally vulnerable regions. Chennai was simultaneously submerged under floodwaters for several days, resulting in deaths and widespread destruction.
Read also | El Nino to hit food grain production in 2023-24 crop year
In the 2023 El Niño, India experienced a 36 percent rainfall deficit in August alone. The worst affected districts included Satara, Nashik and Raigad in Maharashtra, West Nimar in Madhya Pradesh, Balangir in Odisha and Korba in Chhattisgarh.
Historically, the regions most prone to drought during El Niño cycles include southeastern Maharashtra, northern Karnataka, Andhra Pradesh, Odisha, Gujarat and Rajasthan.
It is reported that 60 percent of Indian farmers are completely dependent on monsoon rains during the kharif harvest season, so this year’s rains are exceptionally high. The IMD is expected to issue an updated forecast in the last week of May, which will provide more clarity on the trajectory of the El Niño cycle and its likely impact on regional rainfall distribution.
