Surface urban heat islands are usually documented in large cities, yet small historic coastal settlements, where dense masonry fabric coexists with vegetation, are rarely monitored. This study quantifies the surface urban heat island (SUHI) intensity of Mozambique Island (Ilha de Moçambique), a UNESCO World Heritage Site of about 1.5 km2, and its evolution between 2013 and 2024. Forty-eight dry-season (May–October) Landsat 8/9 Collection 2 Level-1 scenes of WRS-2 path 164/row 070, using the least-cloudy acquisition available in each target month, were processed to land-surface temperature (LST) with the single-channel radiative transfer equation, using atmospheric parameters from the NASA Atmospheric Correction Parameter Calculator, NDVI-based emissivity and Fmask quality control. SUHI intensity was defined as the difference between urban LST and a land-vegetated reference from which pixels within 100 m of the high-water line were excluded, and four scenes per year were averaged into twelve annual values. Mean LST over the period was 31.2 °C in Stone and Lime Town and 29.1 °C in Macuti Town. Island-wide LST increased by 0.148 °C yr−1 (p < 0.001), most rapidly in Stone and Lime Town (0.180 °C yr−1) and more slowly in Macuti Town (0.117 °C yr−1); SUHI intensity in the heritage core rose from 2.8 to 4.1 °C. Built-up cover correlated positively with LST (r = +0.72 and +0.84) and vegetation cover negatively (r = −0.68). Because Band 10 has a native thermal resolution of 100 m, and only 2–5 independent footprints span the island, the results are interpreted at the district and neighbourhood scale; the 30 m grid adds no thermal information. The 95% confidence interval of the island-wide trend is +0.080 to +0.216 °C yr−1.



