Madagascar’s Changing Climate: Why a Cold September Does Not Contradict Global Warming
Madagascar has one of the most unique environments on Earth. Its forests, wetlands, coral reefs, and exceptional biodiversity support millions of people and contain thousands of species found nowhere else. However, Madagascar is increasingly exposed to the consequences of climate variability and climate change.
A particularly interesting question arises during this September 2026: if Madagascar is experiencing climate change and global warming, why can the country still feel very cold during this period?
The answer lies in the difference between weather and climate. Weather describes conditions over hours, days, or weeks, whereas climate describes patterns over much longer periods, usually several decades. A cold day or even a cold month does not contradict a long-term warming trend.
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| Plage à Sambava, Madagascar. Photo prise par Mamisoa Raveloaritiana sous licence libre |
September and Madagascar’s cool, dry season
September occurs toward the end of Madagascar's cool and relatively dry season. Because of the country's large size, complex topography, and different climatic regions, temperatures vary considerably between the highlands, the eastern and western coasts, and the south.
The central highlands, including the region around Antananarivo, can experience particularly cool nights and mornings because of their elevation. Consequently, feeling cold in September is not, by itself, evidence of an abnormal climate.
Climate datasets from the World Bank's Climate Change Knowledge Portal use the 1991–2020 period as a reference climatology and provide monthly and seasonal temperature and precipitation data for Madagascar. The portal also provides historical ERA5 data extending back to 1950, allowing scientists to distinguish normal seasonal variability from longer-term changes.
Madagascar is nevertheless warming
Although individual days can be cold, long-term observations show a warming tendency in Madagascar.
An analysis published in the Journal of African Earth Sciences examined satellite-derived land-surface temperatures from 2000 to 2019. The study estimated that Madagascar's average land-surface temperature increased by approximately 0.338°C per decade during that period. The strongest warming occurred in southern Madagascar, where the estimated increase reached approximately 0.429°C per decade. The researchers also identified particularly strong warming along parts of the eastern coast and in southern areas affected by deforestation.
Another assessment reported by the International Monetary Fund, using Madagascar's climate-risk information, found that the country's average temperature during 1991–2020 was about 0.53°C higher than the 1960–1990 average. It also reported a long-term increase in the number of very hot days and tropical nights.
These numbers are important because they demonstrate why scientists do not determine climate change simply by asking whether today's weather is hot or cold. The important question is whether the statistical distribution of temperatures is changing over decades.
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What about rainfall?
Temperature is only one part of Madagascar's changing climate. Rainfall is more complicated because it varies substantially from region to region.
The IMF's assessment reports substantial regional and seasonal variability in Madagascar's precipitation since 1961. It also identifies declining annual rainfall in parts of the central and eastern coastal regions between 1961 and 2005, together with reductions in winter and spring rainfall in many parts of the country. In some regions, these changes have been associated with longer dry periods.
This is particularly important for Madagascar because a large part of the population depends directly or indirectly on agriculture. Changes in the timing or reliability of rainfall can affect planting, crop growth, water availability, and food security.
Drought and extreme weather
Climate change is also affecting the risks associated with extreme events.
Madagascar is already vulnerable to droughts, tropical cyclones, floods, and other hazards. Recent research published in 2026 found a statistically significant atmospheric warming trend of approximately 0.22°C per decade over Madagascar during 1979–2021. The study also identified increasing trends in atmospheric and marine heatwaves and reported an increase in the frequency and duration of meteorological droughts.
The country's vulnerability is particularly serious in the south. During the severe 2021–2022 drought, rainfall in southern Madagascar was reported to be around 70% below normal. Such conditions can have devastating consequences for agriculture, water supplies, ecosystems, and food security.
So, why can Madagascar still be cold?
This is perhaps the most important scientific point.
Global warming does not mean that every location is warmer every day.
The climate system naturally produces variability. Atmospheric circulation, elevation, ocean temperatures, rainfall, cloud cover, and regional weather systems can all influence temperatures during a particular week or month.
Therefore, Madagascar can experience a cold September even while its long-term average temperature is increasing.
Imagine a person's height being measured over several years. If the person's average height is increasing, they can still be shorter on one measurement than on another because of measurement conditions. Similarly, a warming climate can contain individual periods that are unusually cool.
Scientists therefore examine decades of measurements rather than isolated weather events. The World Bank's climate datasets specifically distinguish year-to-year variability from long-term trends, and their historical temperature records show a warming signal in many regions, particularly toward the late twentieth and early twenty-first centuries.
Why Madagascar is particularly vulnerable
Madagascar's vulnerability does not come only from temperature increases. It results from the interaction between climate change and existing environmental pressures.
Deforestation, habitat degradation, soil erosion, water scarcity, and dependence on rain-fed agriculture can make communities and ecosystems less resilient to changing climate conditions.
This creates a potential cycle:
Climate change → altered rainfall and temperature → greater pressure on agriculture and water → increased pressure on forests and land → greater environmental degradation → reduced resilience to future climate impacts.
Madagascar's biodiversity makes this problem even more significant. Changes in temperature, rainfall, drought, and habitat can affect species that have evolved under very specific environmental conditions.
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What should Madagascar do?
Responding to climate change requires both mitigation and adaptation.
Adaptation could include improving water management, developing climate-resilient agricultural practices, strengthening early-warning systems, improving cyclone and drought preparedness, and protecting ecosystems that provide natural protection against climate hazards.
Protecting forests is particularly important. Forests store carbon, regulate water, protect soils, and provide habitats for Madagascar's unique wildlife. Preventing deforestation can therefore provide both climate and biodiversity benefits.
Madagascar can also improve its ability to monitor climate change. Long-term weather stations, satellite observations, and climate models allow scientists to determine whether changes observed today represent normal variability or part of a longer-term trend.
Conclusion
The fact that Madagascar can feel unusually cold in September does not contradict climate change. September is normally part of the country's cool and dry season, particularly in the highlands, and short-term variations in temperature are expected.
The stronger scientific evidence comes from long-term observations. Research indicates that Madagascar has experienced significant warming, including an estimated 0.338°C per decade increase in land-surface temperature between 2000 and 2019, while another assessment found that average temperatures in 1991–2020 were approximately 0.53°C higher than during 1960–1990. Recent research has also identified increasing heat extremes and drought risks.
Therefore, the real climate-change question for Madagascar is not “Why is it cold today?” but rather:
“How are Madagascar's long-term temperature, rainfall, drought, and extreme-weather patterns changing, and what will those changes mean for the country's people and extraordinary biodiversity?”
Key scientific sources:
World Bank – Climate Change Knowledge Portal: historical climate data, ERA5 observations, seasonal climatology, and climate projections for Madagascar.
Journal of African Earth Sciences (2022): analysis of Madagascar's land-surface temperature from 2000–2019, including the estimated 0.338°C/decade national warming trend.
International Monetary Fund (2024): Madagascar climate-risk assessment, including the 0.53°C increase between the 1960–1990 and 1991–2020 periods and information on drought and rainfall trends.
Weather and Climate Extremes (2026): recent research on atmospheric warming, heatwaves, marine heatwaves, and droughts in Madagascar from 1979–2021.
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