🇹🇱Timor-Leste

Timor-Leste (14,874 km²) occupies the eastern half of Timor Island plus the Oecusse exclave and Atauro and Jaco islands between 8°–10°S, 124°–128°E, straddling the volatile transition zone where the Australian tectonic plate collides with the Eurasian plate, creating rugged mountainous terrain rising to 2,963 m at Tatamailau (Ramelau) and intensifying orographic precipitation.

The nation's climate is tropical wet-dry monsoon (Köppen Am/Aw), governed by the annual migration of the Intertropical Convergence Zone: the austral summer northwest monsoon (November–April) delivers torrential rains averaging 1,500–2,000 mm concentrated in 80% of the annual total, while the southeast trade winds (May–October) bring a pronounced dry season with monthly rainfall below 50 mm.

Mean annual temperatures range from 27°C along the northern coast (including capital Dili) to 16°C in high-altitude interior valleys, with relatively modest seasonal variation typical of equatorial latitudes. The steep topography amplifies flood and landslide hazards: narrow coastal plains transition abruptly to mountains dissected by short, steep river catchments that can discharge severe flash floods within hours of intense rainfall.

Timor-Leste remains one of Earth's most climate-vulnerable nations, with subsistence agriculture supporting over 60% of the population directly dependent on increasingly erratic monsoon patterns, accelerating sea-level rise threatening coastal settlements, and intensifying extreme weather events straining minimal infrastructure and early-warning capacity.

Dili (northern coast, 8.5°S, elevation 11 m) averages 27°C in July (dry season) and 28°C in January (wet season peak) with approximately 900–1,200 mm annual rainfall concentrated November–April, though totals vary dramatically year-to-year with ENSO phases.

The severe April 2021 Cyclone Seroja floods killed over 40 people in Dili and surrounding areas, destroyed more than 4,000 homes, displaced 20,000 residents, and marked the worst flooding disaster in decades when the cyclone's outer rainbands stalled over eastern Timor, dropping over 200 mm in 48 hours and overwhelming drainage infrastructure; landslides buried entire hillside settlements while the Comoro River breached levees, inundating low-lying neighborhoods.

The January 2020 Tasi Tolu floods near Dili killed four and displaced hundreds when localized convective storms dumped extreme rainfall on already-saturated catchments. The severe 2015–16 El Niño drought damaged subsistence maize and cassava production, triggering acute food insecurity across rural highlands and forcing emergency aid interventions for over 100,000 people as the monsoon failed and water sources dried.

The November 2023 heatwave drove coastal temperatures above 36°C for consecutive days, straining Dili's intermittent electricity grid and overwhelming rudimentary health facilities. Baucau (northern coast, 123 m elevation) records similar temperatures with slightly higher rainfall near 1,400 mm.

The mountainous interior experiences cooler conditions: Same (elevation 525 m) averages 25°C with over 1,800 mm, while high valleys near Tatamailau drop to 12–15°C and receive 2,500+ mm, supporting montane forests and cloud cover. Sea-level rise projections (0.8–1.2 m by 2100 under moderate scenarios) threaten Dili and coastal villages with permanent inundation and saltwater intrusion into aquifers, while warming Indian Ocean waters intensify tropical cyclone formation in the Timor Sea corridor.

Our archive covers 1 Timorese cities with daily ERA5 reanalysis data going back to 1940. The warmest July averages occur in Dili, around 29.9°C, while Dili records the coldest January nights near 25.5°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1.1°C.