Author: The World Bank Group
Site of the publication: Climate Change Knowledge Portal
Type of publication: Report
Date of publication: 2025
Country Overview
Benin is a small tropical country in West Africa, covering about 114,763 km2 (reference). It borders Togo to the west, Nigeria to the east, and Burkina Faso and Niger to the north. Benin’s population is approximately 14 million people, the majority of whom reside in the low-lying southern coastal plain (including major urban centers like Cotonou and Porto-Novo). The country is divided into 12 departments or administrative divisions.
Although a small country with generally low elevation (most below 400 m), Benin has varied topography. The coastal area in the south is flat and sandy, with lagoons and marshes. Further inland is a fertile, mostly flat plateau with a few hills. The Atakora Mountains occupy the northwest, while the Niger plains lie in the northeast.
This diverse landscape, together with an economy that heavily depends on agriculture and coastal commerce, makes Benin particularly susceptible to the adverse impacts of climate change from rising temperature, changing sea levels, and shifts in precipitation patterns.
Benin’s diverse terrain and varied topography influences regional climate patterns. The south has a tropical climate with two rainy seasons (March–July and September–November) and two drier intervals, governed by the north-south movement of the Inter-Tropical Convergence Zone. The northern half of Benin has a tropical savanna climate with a single rainy season roughly May–October and a pronounced dry season during boreal winter, influenced by the Saharan harmattan winds.
Agriculture is the backbone of Benin’s economy and rural livelihoods, employing roughly 70% of the workforce, contributing significantly to GDP and export earnings. It is heavily dominated by only a few crops. Five major crops (cassava (35%), yam (32%), maize (10%), rice (8%), and cotton (5%)) together account for nearly 90% of Benin’s agricultural production value (as of 2022). Cassava and yam (root/tuber crops) and maize are primary staples for domestic consumption, while cotton is a critical cash crop for export.
The country’s food security and nutrition are closely tied to climate-sensitive agricultural production. Climate change thus presents a direct threat to nutrition through its impacts on crop yields, food availability, and stability of supply.
Climate Overview
Data overview: Historically, observed data is derived from the Climatic Research Unit, University of East Anglia (CRU), CRU TS version 4.08 gridded stations dataset (1901–2023), and from the ERA5 reanalysis collection from ECMWF (1950–2023).
This diverse landscape, together with an economy that heavily depends on agriculture and coastal commerce, makes Benin particularly susceptible to the adverse impacts of climate change from rising temperature, changing sea levels, and shifts in precipitation patterns
Impacts of a changing climate
Hot Days
Extreme heat can endanger people and animals by triggering heat-related illnesses. It also worsens wildfire conditions, harms agriculture, depletes water resources, raises irrigation demands, and drives up energy consumption, creating ripple effects that can destabilize infrastructure, ecosystems, food systems, and communities.
Under the SSP3-7.0 scenario, Benin is expected to see a sharp rise in hot days (Tmax > 35°C), increasing from 97.42 (83.63, 107.78) days per year currently to 147.26 (88.04, 187.95) days per year by 2050; an increase of roughly 10.94 (3.13, 21.54) days per decade. Although coastal regions are projected to experience a less marked increase, the central and northern regions, which are key areas for agriculture, will likely follow the national trend.
In warm countries like Benin, extended periods of high temperatures can stress plants, disrupt growth stages, and lead to increased water loss. The overall impact depends on the severity, timing, and duration of these temperature changes, as well as on the specific temperature tolerances of different crops; therefore, targeted crop yield studies are essential to fully understand the effects.
Additionally, an increase in hot days presents challenges for human well-being. High-risk areas here are defined as locations where, at least once every 50 years, a year occurs with more than 30 days characterized by maximum temperatures surpassing 35°C. Nationally, median exposure to dangerous levels of heat is set to rise from 60% during 1975–2024 to over 86% in 2050–2099 (Table A5).
Not all regions of Benin will experience heat extremes equally. Coastal areas, moderated by the ocean, will remain a bit cooler than the interior. While Littoral, the most densely populated department, is not expected to experience any health risk from hot days, other high-density departments such as Oueme (rising from 3% in 1975–2024 to 22% in 2050–2099), Atlantique (from 1% to 53%), Couffo (from 48% to 100%), and Mono (from 0% to 95%) may not be as fortunate.
This widespread exposure includes rural farming communities; many will face greater difficulty working outdoors and maintaining agricultural outputs. It also has nutrition implications because heat stress can increase human hydration needs and exacerbate conditions like diarrhea, which affects nutrient absorption, particularly in children. Ensuring access to clean water and cooling is thus part of climate resilience for nutrition.
The country’s food security and nutrition are closely tied to climate-sensitive agricultural production. Climate change thus presents a direct threat to nutrition through its impacts on crop yields, food availability, and stability of supply
Tropical Nights
When evaluating population exposure to tropical nights, high-risk areas are defined as those where, at least once every 50 years, there is a year with more than 30 nights exceeding 26°C. Nationally, the proportion of the population exposed to such dangerous conditions is expected to jump from 47% during the historical period to nearly 100% by 2050–2099.
At the regional level, every subdivision in Benin, including high population density departments like Oueme, Atlantique, and Mono, is projected to reach full exposure. This trend poses significant challenges not only to public health but also to agriculture, as certain crops, such as rice, are particularly sensitive to increased nighttime temperatures.
Heat Index
The Heat Index represents how hot it feels by combining air temperature and humidity, assuming shade and light wind. When both temperature and humidity are high, the Heat Index can rise sharply. This makes outdoor conditions feel much hotter than the actual air temperature. As a result, the risk to human health increases significantly.
Projections indicate that the dangerous heat index-reflecting humid, high-temperature conditions will become an increasing concern by the end of the century. Population exposure to high heat index conditions is set to rise significantly; high-risk areas are defined as those where, at least once every 50 years, a year experiences more than 20 days with a heat index exceeding 35°C.
Historically, over 90% of Benin’s population has been exposed to these conditions, a figure projected to reach 100% by mid-century. Regionally, departments such as Littoral (48% exposure during 1975–2024) and Donga (22% exposure during the same period) are expected to achieve full exposure by 2050, meaning that every department will face extreme heat conditions that pose a significant risk, especially for outdoor worker.
Extreme Precipitation
Access to a regular and sufficient supply of water is essential for crop production. Agricultural productivity is affected not only by insufficient water but also by excessive water delivered in short bursts during intense precipitation events. Adequate seasonal rainfall supports healthy crop growth, yet excessive rainfall can lead to waterlogging, nutrient leaching, and an increased risk of crop diseases.
Although coastal regions are projected to experience a less marked increase, the central and northern regions, which are key areas for agriculture, will likely follow the national trend
Similarly, the intra-seasonal distribution of precipitation is also important. Prolonged periods of low rainfall can trigger drought conditions that harm rainfed crops during sensitive stages such as establishment, flowering, and fruiting, while extended periods of heavy rainfall may result in waterlogging and ponding, particularly affecting root and tuber crops.
In a warming climate, the atmosphere’s increased capacity to hold moisture raises the likelihood of heavier precipitation. Despite natural variability in rainfall patterns, there is a consistent though statistically insignificant trend toward higher one-day precipitation levels (rx1day) and more heavy precipitation days (r20 mm) across all departments in Benin.
These changes indicate a propensity for more intense downpours, raising concerns about flash flooding and soil erosion even if annual totals remain similar. On the other hand, the potential for short-term dry spells within the rainy season could also increase if rains become more concentrated, meaning slightly longer gaps between rainy episodes in some scenarios.
SPEI
The Standardized Precipitation Evapotranspiration Index (SPEI) is a drought index that influences crop yields based on its values: positive SPEI values indicate wetter-than-normal conditions, which are generally associated with higher crop yields, while negative SPEI values signify drier-than-normal conditions that can reduce yields depending on the crop type and region. SPEI12, calculated over a 12-month period, smooths out monthly variations and reflects long-term moisture conditions.
In Benin, the SPEI is projected to improve nationally from the historical period to 2041–2060, although some regional variation exists; it is important to note that while an increase in SPEI12 generally has a positive impact on crop production, intra-annual variability such as an increase in extreme precipitation events may in fact have a negative effect.
Floods
High-risk areas are defined as locations where, at least once every 25 years, a year occurs with a 5-day cumulative precipitation above 130 mm. Nationally, these areas are expected to increase from 22% historically to 46% by 2010–2059 and to 58% by 2050–2099.
High-risk areas here are defined as locations where, at least once every 50 years, a year occurs with more than 30 days characterized by maximum temperatures surpassing 35°C. Nationally, median exposure to dangerous levels of heat is set to rise from 60% during 1975–2024 to over 86% in 2050–2099 (Table A5)
Additionally, return period analysis of extreme 1-day precipitation events indicates significant changes under the SSP3-7.0 scenario. Specifically, a 100-year event is projected to become 2.58 (1.14, 7.26) times more likely by 2035–2064 and 5.42 (1.42, 20.13) times more likely by 2070–2099.
As discussed above, the climate change-induced increase in the frequency of these extreme events is expected to lead to more frequent flooding, which can have detrimental impacts on infrastructure, human safety, and agriculture.
Sea Level Rise
Over one-third of Benin’s population resides within the coastal departments of Mono, Atlantique, Littoral, and Ouémé, where livelihoods and infrastructure are highly sensitive to even modest changes in sea level.
Between 1993 and 2024, mean sea levels across the Beninese Exclusive Economic Zone (EEZ) rose by 0.11 m. This historical increase has been driven by sterodynamic changes (thermal expansion and altered currents; 0.033 m), melting of glaciers (0.017 m) and the Greenland Ice Sheet (0.017 m), changes in land water storage (0.017 m), and vertical land motion (0.017 m), with the Antarctic Ice Sheet contributing around 0.011 m.
These drivers have already exacerbated coastal inundation, accelerated saltwater intrusion into groundwater aquifers, and promoted soil salinization. These threats imperil agriculture, fisheries, and freshwater supplies in low-lying coastal plains.
Under the SSP3-7.0 scenario, projections indicate that by 2100, relative sea levels in the Benin EEZ are likely to rise an additional 0.68 m (median estimate), with a very likely range (17th–83rd percentile) of 0.50 m to 0.93 m, and an extreme (5th–95th percentile) range of 0.58 m to 1.14 m. By mid-century (2050), the median increase relative to 2020 is about 0.19 m, already enough to submerge critical wetlands and low-elevation settlements during high tides and storm surges. Moreover, a 0.5 m rise is projected around 2080 (likely range 2066–2102), and a full 1 m rise is expected by 2125 (likely range 2100–2168).
Continued groundwater pumping and subsidence in some areas may amplify these impacts locally. Such rises will intensify coastal erosion, undermine coastal defenses, and heighten the frequency and severity of flooding, demanding urgent adaptation measures in Benin’s hinterland and urban coastal zones.
Natural Hazards
Natural disasters, from floods and droughts to epidemics and wildfires, are catalogued in EM-DAT, a global database covering over 26,000 mass disasters since 1900. Between 1982 and 2022, Benin experienced 20 major floods (3.3 million people affected) and one severe drought (2.1 million people affected), events whose frequency and intensity have been amplified by a warming climate.
Climate change is driving heavier, more erratic rainfall that feeds these floods, already displacing hundreds of thousands in low-lying coastal departments, and deepening drought spells like the one in 1983 that affected over two million people. At the same time, rising seas (0.11 m since 1993; projected to rise further by 0.68 m by 2100 under SSP3-7.0) will exacerbate coastal inundation during storms and high tides, further magnifying flood hazards in vulnerable areas such as Mono and Littoral Agriculture Impacts.
Agricultural Timing and Heat Stress
Benin’s staple crops (cassava, yam, maize, rice, and cotton) are tightly aligned with the June–November growing season, making the reliability of rains and moderate temperatures essential. As highlighted earlier, mean temperatures have risen by 0.26 °C per decade, hot days are set to climb from roughly 97 to 147 days per year by 2050, and tropical nights (Tmin > 23 °C) are projected to exceed 270 nights annually.
Such warming shortens effective growing periods by stressing plants during critical stages like flowering and grain filling, while warmer nights impede plant recovery and accelerate soil moisture loss. Heat-sensitive cereals and rice, already cultivated near their thermal limits, face the greatest yield reductions, threatening both calories and nutrient availability.
Rainfall Variability and Water Management
Long-term rainfall has declined by about 20 mm per year, yet climate change is driving both more extreme downpours and sporadic dry spells within the season. Intense one-day rains heighten flood and waterlogging risks, particularly as high-risk flood zones expand from 22% of the country historically to 58% by late century, while mid-season drought breaks can stall maize and vegetable development.
This variability disrupts the carefully timed planting, growth, and harvest cycles across Benin’s bimodal and monomodal zones. To sustain yields and nutrition, farmers will need to adjust planting dates, diversify crop calendars, and bolster water management through targeted irrigation during dry spells and enhanced drainage to mitigate floods.