Bangladesh could see lower Boro rice production in the coming season as climatologists warn of an exceptionally strong El Niño, which typically brings hotter and drier conditions during the crop’s growing period.
The UN’s weather agency, World Meteorological Organization, said there was an “exceptionally high likelihood of nearly 100 percent” that El Niño will continue through to February.
“El Niño is being supersized before our eyes. The science leaves no room for doubt,” United Nations Secretary-General Antonio Guterres said in a release on Thursday, warning of its global impacts.
The 2026 El Niño is unusually strong and is expected to persist into early 2027, climatologist Rashed Chowdhury, who is currently teaching at Arizona State University, told The Daily Star.
Boro, the country’s largest rice crop, is planted mainly in December-January and harvested in April-May. It accounts for nearly 55 percent of annual rice production, which stood at 2.13 crore tonnes in 2025-26, according to provisional data from the Bangladesh Bureau of Statistics.
The crop relies heavily on irrigation during the dry season, making it particularly vulnerable to rising temperatures and water shortages.
Agricultural experts warn that unusually high temperatures during flowering and grain filling could cause spikelet sterility -- a condition where rice plants fail to produce viable seeds, leaving farmers with empty or partially filled panicles.
Past research shows that El Niño tends to reduce rainfall during Bangladesh’s Boro season, increasing irrigation needs, while higher temperatures could raise evaporative demand.
However, Rashed said it was too early to attribute any specific production loss to El Niño, as Bangladesh-specific temperature and rainfall forecasts would provide a clearer indication of the risk than the El Niño-Southern Oscillation signal alone.
The Bangladesh Meteorological Department has already forecast higher temperatures in the coming months.
For Boro, the main concern is heat shock during flowering, mainly from mid-April, said Sharif Ahmed, a cropping systems agronomist at the International Rice Research Institute’s Bangladesh office.
Daytime temperatures above 35°C and nighttime temperatures above 28°C can cause flower sterility, while prolonged heat during flowering or grain filling can severely reduce yields by leaving grains empty.
Higher temperatures would also increase irrigation demand, a particular concern in the northwest, where groundwater levels are declining and rainfall patterns are changing.
Rajshahi division’s rainfall has declined by 54mm per decade, according to a study based on 1980-2023 data.
A recent Institute of Water Modelling study found groundwater recharge in seven northwestern districts was only 100-210mm, against a normal range of 100-515mm.
Groundwater depth in the region reached 36 metres in 2025, up from 16 metres in 1985, the study showed.
If irrigation demand rises further, farmers may have to pump more groundwater even as its availability declines, Sharif said. An irrigation crisis could therefore make continued Boro cultivation difficult in some affected areas.
Greater variability in pre-monsoon rainfall and upstream runoff could also increase the risk of early flash floods in the haor region, as seen in 2026,
threatening Boro shortly before harvest.
Storms accompanied by rain during harvest could flatten standing rice, submerge the crop and cause the paddy to rot, Sharif said.
He said short-duration, heat-tolerant and locally adapted Boro varieties could help farmers harvest earlier and reduce exposure to extreme heat, flash floods and storms.
Such varieties are available in Bangladesh, but many farmers still choose long-duration varieties because they can produce 10-15 percent higher yields.
Niaz Md Farhat Rahman, principal scientific officer of the Agricultural Statistics Division and a weather and climate change researcher at the Agromet Lab of Bangladesh Rice Research Institute, said there was no reason for panic at this stage, but climate-informed Boro management was needed.
This includes adjusting planting dates by region, using short-duration and heat-tolerant varieties, timely irrigation, Alternate Wetting and Drying, and linking heatwave forecasts with critical crop-growth stages, he said.
Looking beyond Boro, Farhat said the latter part of the 2026 Aman season and the 2026-27 Rabi season could also face climate-related risks.
Above-normal temperatures combined with below-normal or erratic rainfall in some areas could accelerate soil-moisture loss and increase dependence on irrigation.
“Therefore, the most important response is to closely monitor region-specific seasonal forecasts and adjust irrigation scheduling, sowing and transplanting dates, and crop-management practices in advance,” he said.
