The Indian Meteorological Department (IMD) has predicted heavy rainfall in several districts of West Bengal until August 6, 2025, due to a cyclonic circulation over the north Bay of Bengal and a strong monsoon flow.

South Bengal districts: North 24 Parganas, South 24 Parganas, Nadia, Hooghly, Purba Bardhaman, Paschim Bardhaman, Birbhum, Purulia, and Bankura are likely to experience heavy rain at one or two places until Sunday. Kolkata is expected to receive heavy rainfall on Saturday. Thunderstorms with lightning and gusty wind speeds reaching 30-40 kmph are very likely to occur at one or two places over all the districts of south Bengal.

North Bengal districts: Heavy to very heavy rainfall is expected in the sub-Himalayan districts of Darjeeling, Kalimpong, Alipurduar, Jalpaiguri, and Cooch Behar from August 2 to August 4. The situation in North Bengal is already tense due to the heavy water flow from the Teesta River, which has caused inundation in large areas of Darjeeling district due to incessant rains.

Canning in South Bengal and Kalimpong in North Bengal recorded the state's highest rainfall in the 24 hours leading up to 8:30 am on July 31, 2025, at 110 mm.

The Met office had earlier forecast heavy rains over Kolkata and the districts of South Bengal for the two days leading up to July 31, and heavy to very heavy rains in North Bengal districts from Friday onwards. Scattered rains are expected to continue over the South Bengal districts until Sunday.

According to the Regional Meteorological Centre in Kolkata's Alipore, the low-pressure axis currently extends from the northeast Arabian Sea over Gujarat, Madhya Pradesh, Jharkhand, Chhattisgarh, and Gangetic West Bengal to South Bangladesh. The monsoon axis extends to the northeast Bay of Bengal via Sriganganagar, Churu, Gwalior, Khajuraho, Daltonganj, Purulia, and Canning.

The water level of North Bengal rivers like Teesta, Torsa, and Jaldhaka is expected to rise due to the heavy rains. The Teesta River has already risen, inundating large areas of North Bengal, including Teesta Bazar. Water from the river has entered National Highway-20, resulting in the suspension of vehicular traffic between Sikkim and Siliguri in North Bengal.

Due to the influence of these weather systems and active monsoon winds, West Bengal is experiencing a prolonged spell of rains, which is expected to continue for the next few days.