Why Jashore-Chuadanga experiencing heatwaves?

Natore's Lalpur used to be the hottest place in Bangladesh. However, for the last dozen years, that place has been overtaken by Chuadanga district, located in the southwestern region of the country. Last Saturday, the mercury rose above 42 degrees Celsius in this district. It's not just this year; for the past 12 years, during the summer season, Chuadanga and its neighboring districts have been experiencing intense to extremely intense heatwaves. This region often experiences the highest temperatures in the country. With the onset of the month of Baishakh, the scorching heat begins to intensify in Chuadanga. It feels like being in a desert during midday. Not only Chuadanga, but its neighboring districts like Jessore, Kushtia, Meherpur, Jhenidah, and Khulna also face hotspots of heat during the summer.

Now the question arises, why do these districts in the southwestern region of the country have higher temperatures compared to other areas? The biggest reason for this is that Bangladesh lies near the Tropic of Cancer. Chuadanga and its neighboring districts are located below this Tropic. These districts receive more direct sunlight due to their position relative to the Tropic of Cancer. During the period from March 21 to June 21, the sun's rays are most intense along the Tropic of Cancer. Since Bangladesh is positioned around 23 degrees north latitude and the Tropic of Cancer lies close to 23 degrees, these regions receive the highest solar radiation. Consequently, the highest solar radiation falls on these areas, resulting in higher temperatures. Additionally, during the month of April, Bangladesh is closest to the sun compared to other times, which further contributes to higher temperatures in this region.

Moreover, Jessore, Chuadanga, Meherpur, Kushtia, and Khulna districts are characterized by extensive flatlands. Furthermore, to the west of these districts lies the vast expanse of West Bengal. The vast stretches of land contribute to three methods of heat transfer: conduction, convection, and radiation. Due to the flat terrain, heat is transferred more efficiently through conduction in this region. Consequently, the entire region experiences higher temperatures due to direct heat transfer.

On the other hand, the southwestern area of Chuadanga district experiences an increase in temperature due to the influx of aquatic vapor. The western part of the Sundarbans is located in Khulna and Chuadanga districts. The Bay of Bengal acts as a source of aquatic vapor. The aquatic vapor from the Bay of Bengal enters this region, and due to the wind, the amount of aquatic vapor in the air is higher in this region compared to other areas. As a result, the temperature also increases.

Apart from that, the western part of Bangladesh's Jessore, Kushtia, Rajshahi, Meherpur, and Khulna regions border India's West Bengal, Bihar, Jharkhand, and Madhya Pradesh. Intense hot winds blow directly into the southwestern region of Bangladesh from these regions in India. This wind then travels further to places like Rajbari, Faridpur, Gopalganj, Bagerhat, and Barishal. However, due to the abundance of water bodies, rivers, and vegetation in these areas, the heat is comparatively less intense. In contrast, in the southwestern districts, there is less water bodies and vegetation, resulting in the heat not being dissipated. Hence, the intensity of heat is higher in these areas.

Since Bangladesh's independence, the highest recorded temperature was 43.2 degrees Celsius on May 21, 2014, in Chuadanga, which remains the highest temperature recorded in the district to date. In the subsequent years, temperatures have crossed 40 degrees Celsius multiple times. Last Saturday, the temperature crossed 42 degrees Celsius in Chuadanga. Another reason for this is the lack of heavy rainfall. When a heatwave begins in an area, if the release of heat is not rapid, then the temperature rises. One of the reasons for the slow release of heat is the increase in carbon dioxide, decrease in vegetation, and decrease in water flow, all of which are present in this region.

Additionally, the geographical location of this district also contributes to the current intense heat flow. At this moment, Bihar, Madhya Pradesh, and Kolkata in India are experiencing a heatwave. When the temperature is high in West Bengal, it affects this region as well. Moreover, the combined effect of low pressure and internal temperature rise causes the entire southwestern region, including Jessore, Kushtia, and Chuadanga, to remain sweltering hot in April. A similar situation persists in May as well. Therefore, until the monsoon arrives, the residents of the entire southwestern region, including Jessore and Chuadanga, will have to endure the peak of the heatwave. The current situation in this region seems like lines from a poet's poem, "The sun is scorching today, raining fire; it seems evident, the end of all creation. The gates of hell have opened wide; everything is burning, only cries are heard."