🇸🇸South Sudan

South Sudan (approximately 644,000 km²) spans the tropical wet-dry savanna zone between 3°–13°N in the Upper White Nile Basin, encompassing one of Africa's most dynamic and vulnerable climate systems. The young nation (independent since 2011) features diverse topography: the vast Sudd wetland system, the largest freshwater wetland in the Nile Basin, averaging over 30,000 km² and extending to over 130,000 km² in the wet season, acting as a massive evaporation sink where roughly half the water entering it is lost; the clayey flood plains of the Sobat and Bahr el Ghazal rivers experiencing seasonal inundation patterns; the southeastern Imatong Mountains reaching 3,187 m at Mount Kinyeti with relatively higher rainfall; and the semi-arid northern borderlands transitioning toward Sahel conditions.

The climate is predominantly Köppen Aw (tropical savanna), with mean annual temperatures of roughly 27–30°C across the lowlands and much cooler conditions in the Imatong highlands. Annual precipitation averages 900–1,200 mm across most of the country, concentrated in a single May–October wet season driven by the Intertropical Convergence Zone migration, with the Imatong Highlands receiving about 1,500 mm while northern areas drop to around 700 mm. This rainfall concentration creates extreme seasonal contrasts in hydrology, agriculture, and habitability, making South Sudan acutely sensitive to climate variability and change.

Juba (southern clay plains, elevation 550 m, 4°51'N) sees highs of about 38°C in January and 36°C in April, with nights of 22–23°C, and roughly 950–1,100 mm annual precipitation concentrated April–October; the dry season November–March is the hottest time of year, and in March 2024 an extreme heatwave forecast to reach 45°C forced the closure of all schools nationwide.

Wau (western Bahr el Ghazal region) registers highs of about 35°C in December and 38°C in March, with nights of 18–23°C, and 1,100 mm. Malakal (Upper Nile, White Nile riverbank) records highs of about 35°C in January and 39°C in March, with nights of 19–23°C, and 730 mm, situated in the drier northern transition zone.

The severe 2019–2022 multi-year floods inundated vast areas repeatedly: in 2019 a state of emergency was declared across flood-hit Greater Upper Nile and Bahr el Ghazal; 2020 floods struck again on a large scale; 2021 flooding affected over 835,000 people in what the UN called the worst flooding in some 60 years, threatening Unity State; and October 2022 floods affected some 909,000 people.

The 2024 floods, which also hit Jonglei, continued the pattern, with lasting waterlogging transforming formerly arable land into open water. Climate records indicate South Sudan has warmed by more than 0.4°C per decade over the past 30 years, roughly twice the global average rate, and models project further warming by mid-century.

This accelerated warming intensifies evaporation rates in the Sudd, alters rainfall timing and intensity, and creates dangerous climate-conflict feedback loops as pastoralists and farmers compete for shrinking habitable land, exacerbating the ongoing humanitarian crisis in a nation where over 9 million people require humanitarian assistance.

Our archive covers 5 South Sudanese cities with daily ERA5 reanalysis data going back to 1940. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 2.3°C.