The India Meteorological Department (IMD) on Sunday, 13 September 2026 forecast a gradual reduction in rainfall across south Bengal, bringing relief to residents of Kolkata and surrounding districts, even as north Bengal braces for continued heavy showers through the week. Scattered light to moderate rain with thunderstorms is expected to persist in the south, but no heavy-rain warning is currently in place for the region.

Current Weather System

According to the Met Department, the low-pressure area that had been influencing the region is now situated over south Chhattisgarh and is no longer expected to significantly impact West Bengal. The monsoon trough currently extends from Jaisalmer in Rajasthan to Gopalpur in Odisha before stretching into the east-central Bay of Bengal.

For Kolkata, officials forecast light to moderate rain accompanied by thundershowers, with gusty winds at speeds of 30 to 40 kilometres per hour. Relative humidity in the city stands between 77 and 95 per cent. The maximum temperature in Kolkata on Saturday was recorded at 31.02 degrees Celsius — 1.03 degrees below normal — while the minimum was 27.01 degrees Celsius, marginally above normal by 0.07 degrees.

North Bengal Yellow Alerts: District-Wise Forecast

While south Bengal gets a reprieve, districts in north Bengal remain under active weather alerts this week. The IMD has issued a Yellow Alert for heavy rain across several districts on consecutive days:

Monday: Yellow Alert for heavy rain in Darjeeling, Jalpaiguri, and Alipurduar districts, with the possibility of scattered rain across all remaining north Bengal districts.

Tuesday: Yellow Alert for heavy rain in Kalimpong and Jalpaiguri districts.

Wednesday: Yellow Alert extended to Darjeeling, Jalpaiguri, Alipurduar, and Cooch Behar districts.

Thursday: A Yellow Alert for heavy rain with thundershowers at isolated locations in Jalpaiguri and Alipurduar districts. After Thursday, rainfall is expected to ease in north Bengal as well, barring the formation of a fresh weather system over the Bay of Bengal.

What South Bengal Can Expect Next

Rainfall activity over south Bengal is forecast to diminish progressively over the next five days. The Met Department has indicated that while thundershowers may continue intermittently, no sustained heavy-rain episodes are anticipated. This offers a notable contrast to the preceding days when the active low-pressure system brought significant precipitation to the region.

Notably, the transition in the monsoon pattern aligns with mid-September trends, when the monsoon axis typically begins shifting northward before its gradual withdrawal from northwest India. The absence of a new low-pressure system in the Bay of Bengal will be the key variable determining whether north Bengal's respite arrives on schedule.

Outlook and Watch Points

Authorities and residents in the Darjeeling hills and Dooars region — already susceptible to landslides during heavy monsoon spells — should remain on alert through at least Thursday, 18 September. Any new cyclonic circulation developing over the Bay of Bengal could extend the high-rainfall period beyond current forecasts. Disaster management officials have not yet issued any evacuation advisories, but the Yellow Alerts serve as early warnings for preparedness.