🇹🇿Tanzania

Tanzania (947,303 km²) is crossed by the Great Rift Valley and has a mainly tropical climate with strong regional contrasts, from a tropical savanna coast along the Indian Ocean and a semi-arid interior around Dodoma to subtropical highland climates around volcanic peaks including Africa's highest summit, Mount Kilimanjaro (5,895 m).

The coastal belt receives 1,000–1,500 mm annually driven by the bimodal monsoon regime: long rains (masika, March–May) and short rains (vuli, October–December), governed by the seasonal migration of the Intertropical Convergence Zone and Indian Ocean Dipole phases.

The interior central plateau (1,000–1,200 m elevation) transitions to semi-arid savanna with 500–800 mm concentrated in a single November–April wet season, supporting miombo woodlands. The Southern and Eastern Highlands rise to 2,000–3,000 m with heavy orographic precipitation, while the volcanic Northern Highlands around Kilimanjaro and Mount Meru (about 4,560 m) sustain montane forests and intensive agriculture.

Kilimanjaro's glaciers have severely retreated, losing almost 85% of their 1912 ice cover (11.40 km²) by 2011, with projections indicating near-complete disappearance by about 2040–2060 under current warming trajectories, a stark indicator of accelerating regional climate change.

Tanzania ranks among the world's most climate-vulnerable nations: about half of the 65 million population works in predominantly rain-fed agriculture, coastal settlements face cyclone exposure and sea-level rise, and erratic rainfall patterns trigger cascading humanitarian crises across food security, water availability, and displacement.

Dar es Salaam (coastal lowland, 6.8°S) sees July highs of about 30°C with nights near 19°C (cooler dry season) and January–February highs of 32–33°C with nights near 25°C (hot humid season peak), with approximately 1,100 mm annual rainfall split between an April peak (about 255–265 mm) during masika and November (about 115–125 mm) during vuli, though inter-annual ENSO and IOD variability causes extreme swings.

Tanzania experienced major hydrological and geological hazards between 2019 and 2024. The November–December 2023 El Niño event brought heavy rains and flooding to several regions, which coincided with a cholera outbreak under way since September 2023.

Recurrent poor rains have reduced water availability and livestock production, contributing to food insecurity. In early December 2023, floods and landslides in Hanang District in Manyara region killed at least 88 people, and in April 2024 floods and landslides killed at least 155 people across Tanzania.

Our archive covers 32 Tanzanian cities with daily ERA5 reanalysis data going back to 1940. The hottest July afternoons are in Shinyanga, with average highs around 29.5°C, while Sumbawanga has the coldest January nights, with average lows near 13.8°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1.3°C.