🇹🇿Tanzania

Tanzania (945,087 km²) spans 1°S–12°S, 30°E–40°E along the East African Rift, encompassing diverse climatic zones from the tropical monsoon coast (Köppen Am) along the Indian Ocean through extensive savanna (Aw) across the central plateau to temperate highland climates (Cwb) surrounding 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 and the Serengeti ecosystem. The Southern and Eastern Highlands rise to 2,000–3,000 m with orographic precipitation exceeding 2,000 mm, while the volcanic Northern Highlands around Kilimanjaro and Mount Meru (4,566 m) sustain montane forests and intensive agriculture.

Kilimanjaro's glaciers have severely retreated approximately 85% since comprehensive mapping began in 1912, shrinking from 11.40 km² (1912) to less than 1.85 km² by 2020, with projections indicating complete disappearance by 2040–2050 under current warming trajectories—a stark indicator of accelerating regional climate change that threatens water supplies for millions downstream.

Tanzania ranks among the world's most climate-vulnerable nations: over 65% of the 65 million population depends directly on rain-fed subsistence agriculture, coastal settlements face intensifying cyclone exposure and sea-level rise flooding Dar es Salaam infrastructure and degrading Zanzibar mangrove ecosystems, and erratic rainfall patterns trigger cascading humanitarian crises across food security, water availability, and displacement.

Dar es Salaam (coastal lowland, 6.8°S, elevation 13 m) averages 25°C in July (cooler dry season) and 28°C in January–February (hot humid season peak) with approximately 1,100 mm annual rainfall split between April peak (180–220 mm) during masika and November (130–160 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 exceeding 400 mm over three weeks to coastal regions, killing 155 people nationwide, displacing 200,000, destroying 236,000 hectares of crops, overwhelming Dar es Salaam drainage infrastructure, and triggering cholera cases.

Between 2019–2022, consecutive short-rains failures across Arusha, Manyara, and Dodoma regions reduced water availability and livestock production, creating acute food insecurity affecting over 3 million people and requiring emergency humanitarian assistance. In April 2024, extreme rainfall on Mount Hanang's unstable slopes triggered a landslide that killed 47 people and displaced hundreds in Manyara region, among Tanzania's major landslide events on record.

Our archive covers 1 Tanzanian cities with daily ERA5 reanalysis data going back to 1940. The warmest July averages occur in Dar es Salaam, around 26.6°C, while Dar es Salaam records the coldest January nights near 25.2°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 0.9°C.