Heavy to extremely heavy rainfall is likely over several districts in North Bengal over the next three days due to a strong monsoon flow and an upper air cyclonic circulation, the India Meteorological Department (IMD) said on Friday.

“Widespread light to moderate rainfall with isolated heavy to very heavy rainfall activity, along with extremely heavy rain at one or two places, is likely over North Bengal during August 2 to 4, 2025,” the IMD stated.

Districts such as Jalpaiguri and Alipurduar are expected to receive extremely heavy rain, while Darjeeling, Kalimpong, and Cooch Behar may witness heavy to very heavy rainfall during this period. The IMD also warned of thunderstorms accompanied by lightning and gusty winds of 30-40 kmph across North Bengal.

Nagrakata in Jalpaiguri district recorded the highest rainfall in the state over the past 24 hours till 8:30 am Friday, receiving 90 mm. In South Bengal, Purulia registered 60 mm during the same period.

A generally cloudy sky with intermittent rain has been forecast for Kolkata till Saturday morning.

The IMD attributed the intensified rainfall to the upper air cyclonic circulation that currently lies over sub-Himalayan West Bengal and its neighbourhood, extending up to 9.4 km above mean sea level and tilting southwestward with height.

“The monsoon trough at mean sea level now passes through Sri Ganganagar, Rohtak, Shahjahanpur, Gorakhpur, Darbhanga, Shantiniketan, Canning and then southeastwards to the northeast Bay of Bengal,” the department explained.

Forecast for North Bengal (Aug 1–7):

• August 2–4: Extremely heavy rainfall likely over Jalpaiguri and Alipurduar; heavy to very heavy rain expected in Darjeeling, Kalimpong, and Cooch Behar.
• August 5–7: Light to moderate showers to continue with isolated heavy rain likely.

Potential impacts in North Bengal include:

• Waterlogging, localised flooding, and landslides in hilly regions of Darjeeling and Kalimpong.
• Traffic disruptions, damage to kutcha roads and homes, and a rise in water levels of rivers like Teesta, Torsha, Jaldhaka, and Raidak.
• The IMD has urged residents to avoid travel through landslide-prone or inundated areas, and for tourists to exercise caution.

Forecast for South Bengal (Aug 1–7):

Light to moderate rainfall is expected across most districts with thunderstorms, lightning, and occasional gusty winds. On August 7, heavy rainfall (7–20 cm) is likely over Murshidabad, Nadia, and North 24 Parganas.

IMD’s advisory for South Bengal includes:

• Preparing for waterlogging in low-lying areas and traffic disruptions in urban centres.
• Avoiding shelter under trees or electrical poles during lightning and staying away from water bodies during storms.