IMD forecasts above-normal rainfall in October as four-month monsoon ends with 8% surplus
India is expected to experience increased rainfall during the post-monsoon season, particularly in the Southern Peninsula. The Southwest Monsoon concluded with an 8 per cent surplus, although East and Northeast India faced severe deficits. The IMD predicts a notably wet transition into winter.
India has officially marked the end of the four-month Southwest Monsoon season, the India Meteorological Department (IMD) said Tuesday. The India Meteorological Department (IMD) delivered a forecast predicting extended wet conditions, with more rainfall than normal expected across the country for October and the subsequent post-monsoon period.
The Southwest Monsoon season (June-September) concluded with a national surplus of 8 per cent. However, the forecast for the coming months indicates that India is set for a notably wet transition into winter.
Above-Normal Rainfall Expected in October
IMD Director General Mrutyunjay Mohapatra said that the country is highly likely to receive above-normal rainfall in October, exceeding 115 per cent of the Long Period Average (LPA) of 75.4 mm.
“Normal to below-normal maximum temperatures are expected in other regions of the country during the month,” he said.
Looking regionally, maximum temperatures in October are projected to be above normal in most areas of East-Northeast and Northwest India.
Post-Monsoon and Northeast Monsoon Outlook
The forecast for the broader post-monsoon season (October to December) also points towards an increase in precipitation.
Most parts of the country are expected to receive above-normal rainfall during this period. The exception is some areas in Northwest India, where rainfall is anticipated to be normal to below-normal.
South Peninsular India
The crucial Northeast Monsoon (October to December) rainfall over the Southern Peninsula is most likely to be above normal, exceeding 112% of the LPA. This forecast specifically covers the five meteorological subdivisions: Tamil Nadu, Coastal Andhra Pradesh, Rayalaseema, Kerala, and South Interior Karnataka.
The IMD attributed this propensity for increased rainfall to the development of low-pressure systems over both the Bay of Bengal and the Arabian Sea, alongside atmospheric intra-seasonal variability and other large-scale processes.
Review of the 2025 Southwest Monsoon
The four-month monsoon season concluded on Tuesday, September 30, 2025, with the country recording a final surplus. India received 937.2 mm of rainfall against the Long Period Average (LPA) of 868.6 mm, registering an 8 per cent surplus.
Despite the overall successful performance, which Mohapatra described as “very successful”, the season was fraught with disasters, including cloudbursts, landslides, and mudslides in various regions.
The surplus was not uniform across the nation. East and Northeast India recorded a significant deficit, totalling 1089.9 mm of rain, which is 20 per cent below the normal of 1367.3 mm. The states of Bihar, Arunachal Pradesh, Assam, and Meghalaya were particularly affected, experiencing deficient rainfall in three of the four monsoon months.
“Rainfall over east and northeast India this monsoon season was the second lowest since 1901. The lowest rainfall (1065.7 mm) in the monsoon season in the region was recorded in 2013,” Mohapatra said.