Dhaka: Southwest monsoon is anticipated to commence in the first half of June across the country, with the likelihood of experiencing 5-7 days of light to moderate thunderstorms this month, as stated by the Bangladesh Meteorological Department.
According to Bangladesh Sangbad Sangstha, the Long Range Weather Forecast for June 2026, released on June 1, highlights the potential development of a Low Pressure System over the Bay of Bengal, with one system possibly intensifying into a monsoon depression. Rainfall is expected to be below normal nationwide, while day and night temperatures are likely to remain above normal. The forecast also indicates the occurrence of two to three mild to moderate heatwaves in isolated areas throughout June.
The country's major river systems are predicted to flow normally during this period. However, isolated heavy rainfall could temporarily raise water levels in rivers situated in the northern, northeastern, and southeastern regions.
An Expert Team on Long-Range Weather Forecasting convened on June 1, 2026, at the Storm Warning Centre in Dhaka, where they analyzed data from May 2026. Official data indicates normal rainfall levels, with variations across different regions. The Chattogram, Khulna, and Barishal divisions experienced below-normal rainfall, while other divisions recorded above-normal rainfall.
Throughout May, Bangladesh faced moderately heavy to very heavy rainfall on several occasions and widely experienced light to moderate rainfall accompanied by thunderstorms and gusty winds. The highest daily rainfall was recorded in Dinajpur at 144 mm on May 13, 2026.
A mild heatwave, linked to a thermal low over West Bengal, India, and adjacent regions, affected parts of Bangladesh during late May. The temperature peaked at 38.0°C in Chuadanga on May 18, 2026, while the lowest was 18.4°C in Sylhet on May 3, 2026. Overall, the observed meteorological conditions during May largely conformed to the monthly forecast.