The India Meteorological Department (IMD) revised its prediction for the rainfall during the Southwest Monsoon (SWM) season on May 29, 2026, to 90 per cent of the long period average (LPA). There is a 60 per cent chance of a deficient SWM season which could mean many regions undergoing much drier than normal conditions or even droughts. Below normal rainfall in June and heightened temperatures could lead to above normal heatwaves over many regions in the country.
SWM is said to be below normal when the predicted rainfall for the season is 90-95 per cent LPA for the country. The LPA for the monsoon is defined as the average rainfall between 1971 and 2020 and is around 868.6 mm. When rainfall is below 90 per cent of LPA, it is a deficient monsoon season.
Earlier, on April 13, the weather agency had predicted monsoon rainfall to be 92 per cent of the LPA with a 35 per cent chance of a deficient rainfall season.
Among different homogeneous regions in the country only northeast India may experience normal rainfall of 96-104 per cent of the LPA. The rainfall could be below normal for northwest (<92 per cent of LPA), central and south peninsular (<94 per cent of the LPA) India.
The rainfall over what is known as the monsoon core zone where most of the agriculture is still rain-fed and comprises of regions in central, western and eastern India would also be below normal (<94 per cent of LPA). This could further add to the agricultural distress in the region.
“During June to September 2026, below-normal seasonal rainfall is most likely over most parts of the country, except some areas over Northwest and northeast India, eastern parts of south peninsula and adjoining areas of east-central India and isolated pockets of East India, where normal to above normal rainfall is likely,” said IMD in a press statement.
Additionally, IMD estimated that there was a 60 per cent forecast probability for a deficient SWM season in 2026 and 24 per cent chance of a below normal rainfall season which means that there is a 84 per cent overall chance of rainfall being below normal or deficient.
The decreased rainfall may start affecting India from June onwards with a forecast of rainfall less than 92 per cent of the LPA along with increased temperatures during day and nighttime and above normal heatwaves in many regions.
In terms of maximum temperatures or daytime temperatures, many areas in Jammu and Bihar and a few areas in Punjab, Himachal Pradesh, Uttarakhand, West Bengal, Madhya Pradesh, Maharashtra, Mizoram, Tripura could be below normal in June 2026. In the rest of the country, maximum temperatures could be above normal or above normal.
In terms of minimum temperatures or nighttime temperatures, only a few areas in southern Odisha and Chhattisgarh and northern Andhra Pradesh could experience below normal temperatures, while the rest of the country could undergo normal or above normal nighttime temperatures in June 2026.
The below normal rainfall and heightened day and nighttime temperatures could lead to heat waves and warm nights over various parts of the country.
“During June 2026, above normal heat wave days are expected over many parts of Uttar Pradesh, Haryana, Punjab, Bihar, Odisha, Chhattisgarh, Gujarat and Andhra Pradesh and isolated regions of Maharashtra, Telangana, Himachal Pradesh, and Tamil Nadu,” said IMD in its statement. “However, below-normal heat wave days are likely over Rajasthan and Jharkhand,” the weather agency added.
“The increased likelihood of heatwave conditions during the June 2026 may have considerable impacts on public health, water availability, power consumption, and essential services. Vulnerable groups, including the elderly, children, outdoor workers, and persons with pre-existing health conditions, are particularly at risk from prolonged exposure to extreme heat,” said IMD in the statement.
“Persistent high temperatures may also place additional stress on infrastructure and resource management systems. In view of the anticipated conditions, State Governments and district administrations are advised to undertake necessary preparedness measures, including ensuring the operational readiness of cooling shelters, availability of safe drinking water, and enhanced health surveillance and emergency response mechanisms,” IMD added.
There is a 92 per cent chance for the development of El Niño conditions in the Equatorial Pacific Ocean during the SWM season, according to the IMD. Further the chances of the development of positive Indian Ocean Dipole (IOD) conditions are not as high.
El Niño is the warmer than normal phase of the El Niño Southern Oscillation (ENSO) phenomenon in the Equatorial Pacific Ocean and has led to the suppression of rainfall during the SWM season before.
When positive IOD conditions are active in the Indian Ocean and western region of the ocean is warmer than the eastern region, monsoon rainfall over India is enhanced countering some of the possible impacts of the El Niño.