Durga Puja festivities in South Bengal, including Kolkata, are likely to be disrupted by inclement weather conditions as the India Meteorological Department has predicted intense rain starting Navami (October 1), with a warning of very heavy rainfall on Dashami (the day after Navami).

While Saptami (September 29) saw mostly sunny skies in Kolkata, with no rain reported overnight, the weather is set to turn dramatically. The forecast indicated scattered thunderstorms and lightning across South Bengal districts on the night of Saptami, accompanied by gusty winds of 30 to 40 kilometres per hour. With a possibility of thunderstorms and lightning in all districts of South Bengal, including Kolkata, there is a heavy rain prediction in Kolkata.

Most southern districts are predicted to be “flooded with very heavy rains” on Dashami. There is a warning of heavy rain in Kolkata, Howrah, West Midnapore, Jhargram, East Burdwan, Birbhum, Murshidabad, and Nadia. Heavy to very heavy rainfall (7 cm to 20 cm) is highly likely in North and South 24 Parganas, Hooghly, and East Midnapore, for which an orange alert has been issued.

As per the weather office, thunderstorm activity with light to moderate rainfall activity is very likely to occur over West Bengal on September 30 and October 1. Under the influence of the anticipated low-pressure area, light to moderate rainfall at most places over West Bengal, with isolated heavy to very heavy rainfall is very likely over some districts between October 2 and 5.

 An upper air cyclonic circulation lies over west-central Bay of Bengal off the north Andhra Pradesh coast between 3.1 and 7.6 km above mean sea level, tilting southwards with height, IMD stated.

“An upper air cyclonic circulation is likely to emerge into the north Andaman Sea today, the 30th September, 2025. Under its influence, a low-pressure area is likely to form over the central parts of the Bay of Bengal around 01st October 2025. It is likely to move west-north-westwards and intensify into a depression over west, central, and adjoining northwest Bay of Bengal around 2nd October. It is likely to continue to move west-north-westwards and cross the south Odisha-North Andhra Pradesh coasts around the morning hours of 3rd October,” read the weather department’s bulletin.