Bangladesh was once known for the varied face of its six seasons, each arriving with its own rhythm and character. Farmers set the times for sowing, tending and harvesting their crops in step with this natural rhythm. In recent decades, however, global warming has visibly disturbed it. The seasonal cycle has broken down, and uncertainty, extremes and irregularity in the weather are becoming ever more marked. The effects reach beyond nature to public health, farm production and the overall balance of the environment.

Recent weather trends paint an increasingly worrying picture. Summer temperatures are rising abnormally: in several heatwaves in 2024 they reached 40-42 degrees Celsius. Recent observations show that from the start of April, mild to moderate heatwaves began in many regions, spread quickly and at one point covered 28 districts, with a highest temperature of 39.7 degrees Celsius recorded in Chuadanga.

Sudden rises within short spans are also notable: between 1 and 2 April, maximum and minimum temperatures rose by about four and a half degrees in some places, a sign of abnormal instability. Winters, meanwhile, bring severe cold waves. In 2025, prolonged cold waves, dense fog and temperatures falling to 5-10 degrees Celsius in the north and north-west were a stark example. In January 2026 winter was relatively short, but intense cold was felt in the first week, and temperatures then climbed rapidly at the start of spring, a clear break in the normal transition between seasons.

These swings directly affect farming. According to a recent report by the Meteorological Department, the heatwave has spread over 28 districts, with a highest temperature of 39.7 degrees Celsius in Chuadanga, and maximum and minimum temperatures rose by about four and a half degrees between 1 and 2 April. The rise threatens damage to major crops such as rice and mango.

Rice yields well when the daytime temperature is below 35 degrees and the night temperature below 26 degrees. Above 35 degrees the grains can become empty, so fields need extra standing water. For mango at the young fruit stage, 25-35 degrees Celsius is ideal; hotter weather or an intense heatwave can leave the fruit small and make it likely to drop. This is increasing risk in crop farming and significantly raising farmers' production costs.

Abnormal temperature swings are also a growing concern for environmental balance and public health. Intense summer heatwaves and sudden winter cold snaps are noticeably increasing harm to health, with colds, fever, heat-related illness, sudden infections and respiratory problems more common recently. Irregular rain, prolonged drought and uneven periods of heavy rain in places are reducing soil moisture, deeply disrupting farm production, irrigation and water management and the long-term balance of natural ecosystems. The effects are sharper in the Barind region, coastal areas and riverine areas, where crop losses, water shortages and loss of soil fertility have grown.

Experts warn that unless such climatic extremes are brought under control, long-term, many-sided damage to farming and the environment cannot be avoided. The distinctness of the six seasons is fading as their effects merge. Sometimes winter comes late, sometimes the monsoon is irregular, and sometimes untimely heavy rain or long drought makes things very complex. Season-based living and farm planning both face more uncertainty, and the most direct impact falls on agriculture, the foundation of the economy, food security and rural livelihoods. Erratic weather is disrupting sowing, tending and harvesting schedules, cutting output and multiplying farmers' risks and financial pressure.

Farming in the Barind region, made up of Naogaon, Rajshahi and Chapainawabganj, is especially challenging, with climate extremes rising over the past decade. In the winter of 2017 temperatures fell close to freezing, and in the summer of 2018 they reached 40-41 degrees Celsius. Temperatures of 41 degrees were recorded in 2022 and 39-40 degrees in April 2023. Long spells of 38-40 degrees and a shortfall in rain raise the risk of desertification. International research has already highlighted growing drought and rainfall deficits in South Asia.

Clear action is urgently needed. It is essential to increase the use of renewable energy to cut carbon emissions, expand social forestry, stop tree felling and protect wildlife. River encroachment and the filling of water bodies must stop, and the natural flow of rivers must be restored. Environmental awareness needs to grow, because every creature from the smallest to the largest plays a part in keeping the environment in balance. Rising sea levels could flood coastal areas and displace large numbers of people. Although river-borne silt is forming some new chars, salinity and waterlogging are steadily increasing the harm to farming and water.

Taken together, Bangladesh stands at a complex environmental crossroads. Tackling the crisis requires coordinated effort, scientific research, sustainable water management, greening and a single plan for regional cooperation. Without timely action there will be no choice but to leave future generations an uncertain and hostile environment.

The writer is a senior agriculturist, columnist and chairman of the DRP Foundation.

Source: Jagonews24. First published in Bengali on The Agro News.