Bangladesh records longest heatwave in 76 years

Rafiqul Islam Azad: Bangladesh is currently experiencing its longest heatwave in 76 years, surpassing the previous record for duration. Last April saw 16 consecutive days of intense heat, but this April has experienced an unprecedented 26-day heatwave, marking the longest period of sustained heat in nearly eight decades.

The Bangladesh Meteorological Department revealed this information after analyzing data from as far back as 1948. The department confirmed that the heatwave has broken a 76-year-old record for its length within a single month of April. The current heatwave began on April 1 and persisted through April 26, affecting various parts of the country.

This ongoing heatwave surpassed the 23-day heatwave of 2019 and the 20-day heatwave of 2010.

Meanwhile, the Meteorological Department recorded the season’s highest temperature of 42.7 degrees Celsius in Chuadanga, a northern district of Bangladesh. However, the record for the highest temperature, 45.1 degrees Celsius, set in 1972 in Rajshahi, still stands.

Meteorologists and climate experts attribute the extreme heatwaves to four main factors: climate change, subcontinental high heat zones, reduced precipitation, and El Niño activity. The reduced number of thunderstorms this year has also contributed to the high temperatures.

Prof. Dr. Ainun Nishat, a Water Resources and Climate Change Specialist, stated that the defining characteristic of climate change is its unpredictability. “The weather’s pattern is disrupted. It’s scorching hot now, but later, the heat may completely subside. The challenge is to adapt to this adverse environment,” he said.

Dr. Abul Kalam Mallick, a meteorologist at the Meteorological Department, noted that the recent heatwave was not only intense but also widespread. He mentioned two primary reasons for the heatwave: climate change and human activities. He added that factors such as volcanic eruptions, ocean current anomalies, El Niño’s impact on the Pacific Ocean, and local influences play a role in the extreme weather in Bangladesh.

Mallick also pointed out that the active phase of El Niño, which lasted until April 16, reduced the easterly wind velocity, decreasing the evaporation rate over the Bay of Bengal, which in turn led to fewer rainstorms. This lack of rain has resulted in clear skies and increased solar radiation for 8-10 hours a day.

Meteorologist Omar Farooq stated that this heatwave was not only longer but also more widespread than in previous years. This year, about 75% of Bangladesh experienced continuous heatwave conditions, a record-breaking occurrence. According to heatwave data from 1981 to 2023, April 2010 saw a maximum of 20 days of mild to severe heatwaves in Rajshahi. Jashore experienced the most heatwave days over the last 43 years, followed by Dhaka and Chuadanga.

Prof. AKM Saiful Islam, Director of the Institute of Water and Flood Management at BUET, explained that the heat increases from the end of March and continues through April. He stated that the current heatwave is linked to global temperature rises, with the average global temperature increasing by 1.3 degrees Celsius, affecting Bangladesh as well.

The experts believe that this heatwave is part of a broader pattern across the Indian subcontinent, with significant hyperthermic zones forming in Bangladesh, India, and Pakistan, including West Bengal.

Meteorologist Md. Shahinul Islam suggested that localized rainstorms might not be enough to break the heatwave. To significantly reduce the heat, major thunderstorms are required. Hot thunderstorms might help cool regions like Dhaka, Khulna, and Rajshahi.