April has been becoming increasingly dangerous in recent years due to heat waves. Last April, the temperature broke a 76-year record. But this year, the mercury has started rising a little earlier than usual. The heat wave this year began in mid-March. Experts believe this condition could last until June, posing serious risks to both lives and nature.
According to the Bangladesh Meteorological Department, temperatures have been rising earlier this year compared to recent years. Yesterday (March 16), a mild heat wave swept over 12 districts, including the capital Dhaka. The highest temperature was recorded at 37.7 degrees Celsius in Baghabari, Sirajganj. Within just a day, Dhaka’s highest temperature rose by more than 1 degree Celsius. On Saturday (march 15), the capital recorded a maximum temperature of 34.9 degrees Celsius, which climbed to 36 degrees Celsius yesterday. The weather forecast suggests that the ongoing heat wave could spread across the entire country.
A mild heat wave is identified when the maximum temperature ranges between 36 and 37.9 degrees Celsius. If it’s between 38 and 39.9 degrees, it’s considered a moderate heat wave. A severe heat wave occurs when the temperature hits between 40 and 41.9 degrees Celsius. Any temperature above 42 degrees Celsius is classified as an extreme heat wave.
This year, winter in Bangladesh was relatively mild. In December and January, temperatures were 0.7 degrees Celsius higher than the normal range typical of that time of the year. Even in February, the temperature was 1.4 degrees Celsius above average, and rainfall was nearly 77 percent lower than usual. At the beginning of February, the highest temperature ranged between 28 and 30 degrees Celsius, but by the end of the month, it had climbed to 33 degrees Celsius. The heat intensified further at the start of March, with heat waves already affecting several parts of the country by mid-month. According to the Bangladesh Meteorological Department’s long-term forecast, temperatures in March and the upcoming April are expected to be significantly higher than usual. Like last year, heat waves are likely to persist for several months. However, the risk of prolonged heat waves may only decrease if there are more thunderstorms or Kalbaisakhi (Nor’westers) compared to last year.
Dr. Md Bazlur Rashid, a meteorologist at the Storm Warning Center of the Bangladesh Meteorological Department, told Bonik Barta, “This year, temperatures have started rising earlier than usual. Today and tomorrow, the temperature is expected to remain high, with little chance of rain. April will be even hotter. Last year, temperatures were lower during this period. The highest temperature during last year’s heat wave was 43.3 degrees Celsius. This year, we expect it to be between 40 and 42 degrees Celsius. Last year saw multiple heat waves, with one lasting up to 35 consecutive days. It’s difficult to say now how long the heat waves will persist this year.”
March typically marks the beginning of warmer weather. However, the Meteorological Department’s forecast suggests that temperatures this month will be much higher than average, with a steady rise across the country.
Professor Fatima Akter from the Department of Meteorology at Dhaka University told Bonik Barta, “It’s normal for temperatures to rise in mid-March. It happens every year. But this time, the lower rainfall has made the heat feel more intense.”
Experts warn that untimely heat waves can have severe impacts on both animals and plants. They noted that such heat waves have been occurring for several years, even before winter has fully ended. However, this year, temperatures have started rising earlier. Major causes include deforestation, increased use of vehicles and air conditioners, and environmental degradation. Experts fear that the heat wave will once again have adverse effects on both lives and nature.
Dr. Mohan Kumar Das, Joint Secretary of the South Asian Meteorological Association (SAMA), has advised caution regarding untimely heat waves. Speaking to Bonik Barta, he said, “It’s normal for temperatures to rise during summer, and this increase usually happens gradually. From March to June, heat waves can intensify across various parts of the country, as we witnessed last year. One concerning factor is the temperature variation—yesterday (Sunday), Chuadanga and Dhaka recorded almost similar temperatures, while Sylhet was significantly cooler. Such differences are alarming. Every year, heat waves lead to numerous fatalities across South Asia. To protect lives in Bangladesh, it’s crucial to have accurate early warnings, identify hotspots, and take appropriate action.”
Professor Zillur Rahman from the Department of Disaster Science and Climate Resilience at the University of Dhaka blamed the lack of rainfall for the early rise in temperature this year. He told Bonik Barta, “This is irregular weather. We’ve been experiencing it for several years, and it has become a global issue. Such climate changes are likely to increase in the future. The main reasons include reduced air humidity, and rising greenhouse gases and carbon dioxide levels. Compared to Dhaka, rural areas are more bearable because they have more trees, water bodies, and fewer tall buildings. It’s difficult to predict how extreme the heat waves will be this year.”
He also emphasized, “Everyone needs to play a role in reducing unbearable temperatures. The government should take action and formulate policies that move away from reliance on air conditioning and greenhouse models. Laws must be enacted to protect the environment.”
This year, winter was milder, followed by a sudden spike in temperature. Professor M Mahfuzur Rahman from the Department of Botany at Jahangirnagar University noted that this shift impacts plants just as it affects humans. He said, “Sudden changes in temperature disrupt the photosynthesis patterns of plants, potentially damaging delicate cells. Environmental changes have already disrupted the ecosystem, and sudden shifts between heat and cold will further harm plant life.”
Every year, temperature records are being broken. Last year was recorded as the hottest in global history, not just in Bangladesh but worldwide. Dr. Md Monwar Hossain, Professor of Biology at Jahangirnagar University, said, “This is a global issue. During such times, animals also struggle in hostile environments. Sudden weather changes from winter can disrupt animal reproduction processes and increase the risk of diseases, ultimately impacting biodiversity. In the coming days, this will be a major challenge. Climate change will continue to pose serious threats.”
The number of the year’s hottest days is no longer limited to April or the summer season; it has also increased during the monsoon. The extension of the summer season and the continuation of heat waves during the monsoon are primarily consequences of climate change. According to the latest data from the Global Climate Risk Index, Bangladesh ranks among the top ten countries most vulnerable to climate risks.
Professor Akhter Hossain Khan from the Department of Soil, Water, and Environment at Dhaka University told Bonik Barta, “Rising temperatures affect all aspects of the environment. Like every year, temperatures are increasing again. Human actions have disrupted the ecosystem, and this will have adverse environmental effects. Diseases among humans are likely to rise, and biodiversity will also be affected.”