North east monsoon South Peninsular India consisting of five meteorological subdivisions (Tamil Nadu, Puducherry & Karaikal, Coastal Andhra Pradesh & Yanam, Rayalaseema, Kerala & Mahe, and South Interior Karnataka) receives about 30% of its annual rainfall during the northeast monsoon season (October to December). Tamil Nadu, Puducherry, and Karaikal receive approximately 48% of their annual rainfall during the northeast monsoon season. Recognising the significance of this period, IMD has been issuing seasonal rainfall forecasts for the south peninsula using statistical models since 1998 and continues to enhance the skill of these forecasting systems. In 2021, IMD adopted a new strategy for issuing monthly and seasonal operational forecasts for rainfall over the country. This approach combines the existing statistical forecasting system with a newly developed Multi-Model Ensemble (MME)–based system. The MME technique use coupled global climate models (CGCMs) from various international climate prediction and research centers, including IMD’s own Monsoon Mission Climate Forecast System (MMCFS). Using this strategy, IMD issues a range of seasonal and monthly forecasts for rainfall and temperature (Maximum & minimum). The rainfall forecast for the post-monsoon season (October to December 2025) is as follows. Long Range Forecast of Rainfall during Post-Monsoon Season 2025 Seasonal rainfall during October to December (OND) over South Peninsular India consisting of five meteorological subdivisions (Tamil Nadu, Puducherry & Karaikal, Coastal Andhra Pradesh & Yanam, Rayalaseema, Kerala & Mahe, and South Interior Karnataka) is most likely to be above normal (>112% of Long Period Average (LPA)). The LPA of rainfall over the South Peninsular India during the post-monsoon season based on data of 1971 to 2020 is about 334.13mm. Most parts of the country are expected to receive normal to above-normal rainfall, except many parts of Northwest India and some parts of extreme south peninsular India and northeast India, where rainfall is likely to be below-normal. It may be noted that while above-normal rainfall can benefit agriculture and water resources, it also brings heightened risks, including flooding, transport disruptions, public health concerns, and ecological impacts. Given these potential hazards, anticipatory actions may be initiated for the season. it is crucial to utilize the early warning services provided by IMD, which include timely impact-based forecasts (IBF) and risk based warnings against heavy rainfall, flood and associated hazards. Authorities are encouraged to adopt a proactive approach by reinforcing infrastructure, developing contingency plans, and responding promptly to forecast/warnings and advisories. Such preparedness can support efficient resource mobilisation, safeguard vulnerable communities, and help protect lives and livelihoods during adverse weather events. Onset of NE monsoon 2025 The Northeast Monsoon rainfall activity has commenced over Tamil Nadu, Puducherry & Karaikal, Coastal Andhra Pradesh, Rayalaseema, South Interior Karnataka and Kerala Mahe on 16th October 2025. Cyclone warnings To view Cyclone warnings, click here. Flash flood warning Bulletin To view Flash flood warning Bulletin, click here. Source : IMD