The Bangladesh Meteorological Department (BMD) has forecast an overall increase in the water levels of the country's major rivers in August as monsoon rainfall continues.
"Due to monsoon heavy rainfall, short-term flooding may occur in the northern, northeastern and southeastern regions of the country," said the monthly climate outlook for August issued by the weather office on Sunday.
The outlook said rainfall is likely to remain normal across the country. One to two low-pressure systems are likely to form over the Bay of Bengal, one of which may intensify into a monsoon depression.
Thunderstorms are likely on five to six days during the month, while both day and night temperatures are expected to remain above normal across the country. It also forecast one to two mild (36-37.9 degrees Celsius) to moderate (38-39.9 degrees Celsius) heatwaves at isolated places during August.
The outlook was prepared following a meeting of the Expert Team on Long-Range Weather Forecasting held at the Storm Warning Centre in Dhaka on August 2.
The meeting analysed various meteorological data and information for July 2026 and observed that Bangladesh recorded 35.6 percent above-normal rainfall during the month.
Normal rainfall was recorded in Mymensingh Division, while all other divisions experienced above-normal rainfall.
During July, three low-pressure areas formed over the Bay of Bengal, two of which intensified into monsoon depressions.
The first low-pressure area formed on July 2 over the northwest Bay and adjoining coastal areas of northern Odisha and West Bengal. It intensified into a well-marked low on July 4 and further intensified into a monsoon depression on July 5.The system moved west-northwestwards and crossed the north Odisha coast near Baleshwar at around 6:00 am on July 6 before gradually weakening and becoming unimportant.
The second low-pressure area formed on July 15 over the northwest Bay and adjoining coastal areas of northern Odisha and West Bengal. It intensified into a well-marked low on July 16 before weakening into a low-pressure area on July 17 and becoming unimportant.
The third low-pressure area formed on July 25 over the northwest Bay and adjoining the Gangetic West Bengal-northern Odisha region. It intensified into a well-marked low over the northwest Bay and adjoining coastal areas of Odisha and West Bengal. Around noon on July 26, it further intensified into a monsoon depression and subsequently developed into a deep depression on July 27 over the northwest Bay and adjoining coastal areas of West Bengal and Odisha.
The system moved west-northwestwards and crossed the West Bengal-Odisha coast at around 6:00 am on July 28. It then continued moving westwards, gradually weakened and eventually became unimportant.
The outlook said heavy to very heavy rainfall occurred at many places across the country during July due to the active southwest monsoon and the influence of the well-marked lows and monsoon depressions.
The rainfall was accompanied by gusty and squally winds and thunderstorms. The highest daily rainfall of the month was 329 mm, recorded at Ambagan in Chattogram on July 8.
A mild heatwave affected some parts of the country on July 3 and 4. The highest maximum temperature of the month was 37.6 degrees Celsius, recorded at Rangpur on July 4, while the lowest minimum temperature was 22.0 degrees Celsius, recorded at Sylhet on July 22, the monthly outlook added.
