Bangladesh is likely to experience higher-than-normal temperatures throughout June, while overall rainfall may remain slightly below the seasonal average, according to the long-range forecast issued by the Bangladesh Meteorological Department’s expert committee.
Officials said the south-west monsoon, which marks the onset of the country’s rainy season, could spread across the entire country during the first half of June. However, despite the expected arrival of the monsoon, rainfall throughout the month may remain somewhat below normal levels.
Md. Mominul Islam, Acting Director of the Bangladesh Meteorological Department and Chairman of the expert forecasting committee, stated that both daytime and nighttime temperatures are expected to remain above average during June. He added that the country could experience two to three episodes of mild to moderate heatwaves during the month.
Under the department’s classification, a mild heatwave occurs when temperatures range from 36°C to 37.9°C, while a moderate heatwave is recorded when temperatures reach between 38°C and 39.9°C.
The forecast also indicates the possibility of five to seven days of light to moderate thunderstorms across different parts of the country. Meanwhile, one or two low-pressure systems may develop over the Bay of Bengal, with one potentially intensifying into a seasonal low-pressure area.
Expected Rainfall in June
| Division | Forecast Rainfall (mm) |
|---|---|
| Chattogram and Sylhet | 600–630 |
| Barishal | 420–470 |
| Rangpur | 400–420 |
| Dhaka | 330–350 |
| Khulna | 280–300 |
| Rajshahi | 270–290 |
Meteorologist Md. Shahinul Islam of the Storm Warning Centre said scattered rainfall has already begun in several regions, although it is not yet sufficient to significantly ease the ongoing heatwave conditions.
According to him, rainfall has occurred in parts of Bogura, Rajshahi, Netrokona and Rangpur, which may bring localised reductions in temperature. However, it may take another two to three days before the heatwave weakens substantially.
He noted that Dhaka has not yet received any significant rainfall and residents continue to experience hot and uncomfortable weather conditions.
The south-west monsoon has not yet entered Bangladesh and is currently positioned near the coast of Myanmar. Meteorologists estimate that it could reach Bangladesh within the next three to four days.
Review of Weather Conditions in May
Data from the Bangladesh Meteorological Department show that the country recorded an average rainfall of 289 millimetres in May, which was 7.4 per cent above the normal level for the month.
Above-average rainfall was recorded in the Mymensingh, Sylhet, Dhaka, Rajshahi and Rangpur divisions. In contrast, Chattogram, Khulna and Barishal divisions received below-normal rainfall.
The highest single-day rainfall of the month was recorded in Dinajpur, where 144 millimetres fell on 13 May.
Throughout May, the interaction between a western low-pressure system and easterly winds produced moderate to heavy rainfall across most parts of the country, with very heavy rainfall occurring in some areas. Thunderstorms, gusty winds and isolated hailstorms were also reported.
Several rounds of mild heatwaves affected different regions during the month. The highest temperature recorded was 38°C in Chuadanga on 18 May, while the lowest temperature was 18.4°C in Sylhet on 3 May. Despite these fluctuations, the national average temperature for May remained 0.4°C below the long-term average.
River Situation
The monthly outlook suggests that water levels in the country’s major rivers are likely to remain within normal ranges. However, isolated heavy rainfall in the northern, north-eastern and south-eastern regions may cause temporary rises in water levels in some rivers.
Overall, June is expected to be characterised by the gradual advance of the monsoon, periodic thunderstorms, intermittent heatwave conditions and rainfall amounts that may remain slightly below the seasonal norm despite the onset of the rainy season.