Dhaka: The Bangladesh Meteorological Department (BMD) has forecasted short-term flooding in the northern, northeastern, and southeastern regions of the country due to heavy monsoon rainfall, as detailed in their monthly weather outlook.
According to Bangladesh Sangbad Sangstha, the forecast indicates that the water levels of major rivers across the country may rise throughout September, despite the expectation of below-normal rainfall nationwide. The BMD's Long Range Weather Forecast for September 2026 also predicts the formation of 1-3 low-pressure systems over the Bay of Bengal, with one potentially developing into a monsoon depression.
Thunderstorms are expected to occur on 3-5 days during the month, with both day and night temperatures anticipated to remain above normal. Additionally, the forecast suggests that two to three mild to moderate heatwaves, with temperatures ranging from 36°C to 39.9°C, are likely to affect the country.
An Expert Team on Long-Range Weather Forecasting convened on 1 September 2026 at the Storm Warning Centre in Dhaka to analyze data from August 2026. Official records show normal rainfall levels (-5.7%) across Bangladesh during August, with variations in different divisions. Notably, Chattogram and Mymensingh experienced above-normal rainfall, while Sylhet and Barishal saw normal levels, and other areas recorded below-normal precipitation.
August 2026 saw the formation of four low-pressure areas over the Bay of Bengal, two of which intensified into monsoon depressions. The active southwest monsoon, coupled with these systems, resulted in heavy to very heavy rainfall in many regions, accompanied by gusty winds and thunderstorms. The highest daily rainfall was 198 mm, recorded at Hatiya on 5 August 2026.
A mild heatwave affected several areas between 10-12, 22, and 26-30 August 2026. Rajshahi recorded the month's highest temperature at 37.0°C on 27 August 2026, while Narayanganj noted the lowest at 22.6°C on 7 August 2026. Overall, the month's maximum, minimum, and mean temperatures were above normal by 0.8°C, 0.5°C, and 0.7°C, respectively.
The observed weather patterns, including rainfall, temperature, heatwave conditions, thunderstorms, and river conditions, were generally consistent with the monthly weather outlook for August 2026, as reported by the BMD.