Changing Weather and Climate Extremes in Bangladesh: Forecasting Challenges and Policy Pathways for Disaster Risk Reduction
- Mostofa Kamal
- Jan 7
- 7 min read
Bangladesh is one of the most climate-vulnerable countries in the world due to its geographic location, low-lying deltaic terrain, dense population, and dependence on climate-sensitive livelihoods. Home to nearly 180 million people, the country is regularly exposed to a wide range of weather-related hazards including severe thunderstorms, floods, heatwaves, cold waves, cyclones, storm surges, lightning, and sea-level rise. Approximately 19 out of 64 districts lie in the coastal zone, much of which is only about two meters above mean sea level, placing nearly 35 million people at chronic risk from climate extremes and coastal hazards.
Agriculture is the backbone of Bangladesh, employing 41% of the labor force and contributing 15% to the national GDP. Yet, the sector faces escalating challenges due to climate change and extreme weather variability. According to the World Bank, Bangladesh loses approximately $800 million dollars of crop due to weather related events, which makes Bangladesh one of the leading food grain importers in the world.
In recent decades, Bangladesh has experienced noticeable shifts in weather patterns, intensification of extreme events, and growing mismatches between forecast capabilities and societal needs. This article reviews major weather and climate hazards affecting Bangladesh, identifies current forecasting and communication limitations, and offers policy recommendations aimed at strengthening disaster risk reduction (DRR).
1. Severe Thunderstorms
Bangladesh is recognized as one of the world’s most intense severe thunderstorm hotspots, particularly during the pre-monsoon season (March–June), locally known as the Kalboishakhi or Nor’wester season. These storms frequently produce damaging winds, torrential rainfall, hail, and intense lightning. Despite their frequency and destructive potential, severe thunderstorm outlooks are not routinely issued by the Bangladesh Meteorological Department (BMD). This gap leaves farmers, outdoor workers, and rural communities highly exposed, especially during peak agricultural periods. Observations suggest that thunderstorm intensity and associated hazards such as hail and lightning are increasing, likely due to rising atmospheric instability and moisture availability.
2. Severe Hail Events
Bangladesh experiences severe hailstorms during both pre-monsoon and post-monsoon seasons. World’s Heaviest (2.25 lb) Hailstone fall over Bangladesh on April 14, 1986. Destructive hailstorms during pre-monsoon season (March-April-May) cause serious economic losses (e.g., crop damage, property) and social impact in Bangladesh, particularly for farmers lacking insurance. Several scientific studies shows that the frequency of severe hail (hail with greater than 2 cm in diameter) events and hail size shows an increasing trend in the recent decades. Temperature and moisture are tow of the most important ingredients needed to produce large hail. With increasing trend of Global Warming, both of these ingredients are increasing, specially over the tropical countries like Bangladesh and other south Asian countries. Therefore, in the coming decades, the South Asian countries, including Bangladesh may witness more severe hailstorms during summer months. Despite increasing frequency, hail climatology and operational forecasting remain underdeveloped in Bangladesh.
3. Lightning
Bangladesh is among the world’s most lightning-fatal countries, with 300–400 deaths annually. Lightning killed nearly 4,000 people in Bangladesh from 2010 to 2023. In May 2024 alone, 80 people died due to lightning, including 20 subsistence farmers. Although it receives fewer lightning strikes than the United States, fatality rates are much higher due to socioeconomic vulnerability and lack of awareness. Farmers, schoolchildren, fishers, and pedestrians are the most affected groups. An average of 1.73 deaths occurred per day during the pre-monsoon season in Bangladesh from 2013 to 2017 (Ronald et al., 2019). The annual averages for Bangladesh are 114 fatalities and 89 injuries from 1990-2016 (Dewan et al. 2017). Western disturbances and orographic influences from the Himalaya and Meghalaya Plateau play a key role in generating intense lightning outbreaks. A study lead by Kamal et al (2024) finds that the existing government policies on lightning management have significant limitations, including insufficient scientific credibility, ineffective thunderstorm forecasts, and poor risk communication. The study suggested that automated early lightning warning system must be introduced to warn people in advance about intending severe thunderstorm risk. Moreover, a comprehensive lightning education and early warning systems are urgently needed to reduce the lightning-related casualties.
4. Extreme Rainfall Events
Extreme rainfall events are becoming more frequent and intense, driven by increased atmospheric moisture, stalled weather systems, and enhanced land-atmosphere feedback. These events frequently overwhelm drainage systems, damage crops, and trigger urban flooding in cities such as Dhaka, Chattogram, and Sylhet. The lack of high-resolution, impact-based rainfall forecasts limits the ability of communities and local authorities to prepare for these events. Improved use of satellite data, radar observations, and reanalysis products could significantly enhance early warning capacity.
5. Monsoon Rainfall
The South Asian monsoon governs Bangladesh’s hydrological cycle and agricultural productivity. While total seasonal rainfall shows high interannual variability, evidence suggests increasing rainfall intensity and longer dry spells between events. These shifts complicate water management, crop planning, and flood preparedness. Monsoon forecasting skill has improved at seasonal scales, but translating forecasts into actionable guidance for farmers and disaster managers remains a major challenge.
6. Flood
Flooding remains Bangladesh’s most widespread hazard, affecting livelihoods, infrastructure, and food security almost every year. On average, nearly 30% of the country is inundated annually during the monsoon season (June–October). Bangladesh experiences two main types of floods: seasonal river flooding driven by monsoon rainfall and upstream flows, and sudden flash floods during the pre-monsoon. Flood risk is exacerbated by upstream water releases from transboundary rivers, often without prior notification, as well as limited forecasting lead time and coordination. Recent extreme rainfall episodes over eastern Bangladesh have demonstrated how local, regional, and large-scale atmospheric processes can combine to produce devastating flood conditions.
7. Flash Flood
Flash floods primarily affect northeastern Bangladesh during the pre-monsoon season. These events occur with little warning and are particularly destructive for subsistence farmers. A notable flash flood between June 14–17, 2022, resulted in approximately 150 fatalities in the Sylhet Division, highlighting the lethal consequences of insufficient early warning. Flash flood forecasting remains challenging due to rapid hydrological response, complex terrain, and limited real-time data sharing with upstream regions. Strengthening cross-border hydrological cooperation is essential for reducing flash flood impacts.
8. Cold Wave
Although Bangladesh is experiencing overall winter warming, severe cold waves continue to cause significant mortality, especially among low-income populations. From 2000 to 2019, over 5,600 cold-related deaths were recorded nationwide. Cold air advection from the Himalayas, combined with clear skies and weak winds, frequently leads to sharp nighttime temperature drops. Cold wave risk remains underestimated in national disaster planning, and early warning dissemination to rural populations is limited. A recent scientific study lead by Kamal et. al (2025) finds that coldwaves events over Bangladesh can be predicted with more than 80% accuracy 21 days in advance. Improved cold wave monitoring and targeted public health advisories are urgently needed.
9. Heatwaves
Heatwaves are emerging as one of Bangladesh’s most serious climate threats. A recent scientific study by Sanjid et. al (2025) finds that humid heat extremes are increasing far faster than temperature alone, particularly during the pre-monsoon and monsoon seasons. The likelihood of extremely hot and humid conditions has risen dramatically, increasing health risks and reducing labor productivity. Further, the difference between daytime and nighttime temperature is rapidly decreasing which results in increased demand for energy. Bangladesh meets majority of its energy demand through imports. With increasing frequency and intensity of heatwaves in the future, Bangladesh will faced with more energy insecurity in the coming decades. Despite the growing threat, heatwave warning systems and public awareness remain inadequate.
10. Bay of Bengal Cyclone
Bangladesh's coastal zone spans over 580 km and includes territory where 28 % of the population (around 35 million) resides (World Bank). Bangladesh has endured some of the deadliest tropical cyclones in recorded history, including the 1970 Bhola Cyclone, which claimed up to 500,000 lives. Although cyclone mortality has declined due to early warning systems and shelters, economic losses continue to rise. The Bay of Bengal is witnessing potential cyclone intensification linked to warmer sea surface temperatures. Cyclone Remal (May 2024) highlighted the continuing need for accurate forecasts and effective communication. BMD occasionally makes serious forecast mistake (mainly human error) which results in increased number of deaths and property damage during high-impact weather events such as Cyclone, Flood, Thunderstorms, etc. For example, during Cyclone Sitrang, inaccurate forecast by BMD become talk of the country. Former vice-chancellor of Dhaka University and a professor of Disaster Science and Management Department, ASM Maksud Kamal told Daily Prothom Alo, "Talking to the department of meteorology, I felt that there is a lack of workforce qualified to use the modern technology for forecasting meteorology and cyclones.” (October 27, 2022).
11. Storm Surge
19 districts out of 64 are in Bangladesh's coastal region, which lies just 2 meters above sea level. Storm surges associated with tropical cyclones pose the greatest threat to coastal Bangladesh. Low elevation, funnel-shaped coastlines, and dense populations amplify surge impacts. Even moderate cyclones can generate catastrophic flooding when storm surge coincides with high tide. Current surge forecasting and evacuation planning require further refinement to reduce residual risk in coastal communities.
12. Sea-Level Rise
Sea-level rise threatens to permanently inundate large portions of Bangladesh’s coastal zone. Approximately 28% of the population lives along a 580-km coastline, much of it only two meters above sea level. Saltwater intrusion, land loss, and displacement are already affecting livelihoods and ecosystems. Long-term adaptation planning, including managed retreat and coastal infrastructure investment, is essential for national resilience.
13. Weather Forecast Communication
Effective communication is often the weakest link in Bangladesh’s early warning system. Forecast errors by Bangladesh Meteorological Department (BMD), often due to human limitations have led to increased deaths and property loss during cyclones, floods, and storms. Ulike the USA, Canada, UK, Bangladesh lacks professionally trained broadcast meteorologist who can provides daily weather forecasts at television channels, and official bulletins are frequently too technical for vulnerable communities. Indigenous and marginalized groups, such as the Munda community in coastal Satkhira, face additional barriers to accessing forecasts. Citizen-led initiatives such as www.abohawa.com demonstrate how localized, Bengali-language forecasts can fill communication gaps and save lives.
14. BMD Capacity Building and Modernization
The Bangladesh Meteorological Department remains the sole official forecasting authority but faces chronic shortages of skilled personnel, modern tools, and communication capacity. Bangladesh’s current weather forecast acts prohibits weather forecast communication by private enterprise apart from the Bangladesh Meteorological Department. Human errors have contributed to forecast failures during high-impact events. A recent study lead by Kamal et al (2024) shows that in countries like Bangladesh, governments can leverage citizen expertise during high-impact weather events to enhance forecasting capacity. Citizen meteorologist can correct critical forecast errors made by understaffed government meteorological agencies.
Policy priorities should include:
Workforce expansion and advanced training
Modernization of radar, satellite, and modeling systems
Collaboration with citizen meteorologists and media
Adoption of impact-based forecasting frameworks
Policy Recommendations
Strengthen Impact-Based Forecasting tailored to local hazards and livelihoods.
Improve Forecast Communication using local languages, media, and trusted intermediaries.
Formalize Citizen Science Collaboration to enhance surge capacity during extreme events.
Enhance Regional Cooperation on transboundary water management.
Invest in BMD Modernization and human resource development.
Integrate Climate Risk into Development Planning to reduce long-term vulnerability.
Conclusion
Bangladesh’s weather and climate risks are intensifying, but so are opportunities for innovation in forecasting, communication, and policy. Bridging scientific advances with community-centered approaches can significantly reduce disaster losses and strengthen national resilience in a changing climate.
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