Even though temperatures start rising in March, April is typically the hottest month in Bangladesh. On the first day of April, several areas of the country experienced mild heatwaves, which could continue for another three to four days. The Bangladesh Meteorological Department (BMD) has predicted two to four heatwaves this month, along with a possible cyclone.

According to the BMD’s long-term forecast for April, the country may see lower than usual rainfall, while temperatures may remain above average during the month. The country could see two to four mild to moderate heatwaves, with one or two potentially turning severe. Both daytime and nighttime temperatures are likely to be higher than normal.

The average normal temperature for April in Bangladesh is 33.2°C. A mild heatwave occurs when temperatures range from 36°C to 37.9°C. Moderate heatwaves are recorded when temperatures reach 38°C to 39.9°C, while severe heatwaves occur between 40°C and 41.9°C. If temperatures exceed 42°C, it is classified as an extreme heatwave.

Meteorologist Md Shahinul Islam told Bonik Barta, “Over the past 30 years, we’ve seen changes in April’s weather patterns in Bangladesh. There is now less rainfall, while heat levels have increased significantly. This is a result of global climate change. It remains to be seen how the situation will unfold in the coming years.”

Along with the heat, April also brings the risk of nor’westers (Kalbaishakhi storms). Some areas of the country have already experienced these storms. This April, BMD expects five to seven days of moderate thunderstorms with hail, as well as one to three days of severe storms. The Bay of Bengal may also see one or two low-pressure systems forming, with at least one potentially developing into a cyclone.

The BMD also predicts that major rivers in Bangladesh will maintain normal flow in April. But in the second half of the month, heavy rainfall in the northeastern region and upstream areas could lead to a rapid rise in water levels.

Meteorologist Kazi Jebunnesa stated, “A low-pressure system may develop around mid-April. But it’s too early to confirm whether it will turn into a cyclone. The predicted severe heatwave is more likely to occur toward the end of the month. Rainfall is also expected to be below normal.”

This month, rainfall is likely to occur 8 days in Dhaka and Mymensingh, 7 days in Chattogram and Barishal, 13 days in Sylhet, 6 days in Rajshahi and Rangpur, and 5 days in Khulna.

Last year, Bangladesh experienced its hottest temperatures in 76 years, with a record-breaking 35-day heatwave from April to May. In fact, 2023 was recorded as the hottest year in global history. This January also set a new record as one of the warmest ever.

The prolonged heat last year significantly reduced the number of nor’westers. Typically, Bangladesh experiences nine nor’westers in April and 13 in May, but last year, there were only two in April and four in May. However, Assistant Meteorologist Afroza Sultana predicts that this year could be different. She said, “There may be more cloud formation in April and May, increasing the likelihood of nor’westers. As a result, we may not see the same prolonged heatwave as last year.”