As part of the GAIA (ManaGement strAtegy evaluatIon for small-scale fisheries in Atoll lagoons) project, which evaluates the sustainability of socio-ecosystems in semi-enclosed atolls based on the exploitation of clam resources within the context of climate change, several environmental sensors were deployed in Reao Atoll, a semi-enclosed atoll lagoon without reef pass but connected to ocean through numerous shallow spillways (known locally as "hoa") along its southern rim. The lagoon of Reao is composed of three basins with varying depths (the NW basin being the shallowest and the SE basin the deepest). Autonomous oceanographic equipment was deployed at bottom-moored stations, enabling high-frequency sampling and detailed measurements of the lagoon's physical and thermal characteristics. The lagoon was first instrumented with a temperature and pressure logger from mid-December 2016 to late June 2017 at a single location within the intermediate basin. Subsequently, from August 2021 to early April 2024, temperature, pressure, and current loggers were deployed on multiple locations distributed across the three basins, including areas within the lagoon, the "hoa", and the internal reef slope. Temperature sensors were deployed to characterize temporal and spatial variations in lagoon temperature, whereas water level fluctuations, wave climate and ocean-lagoon exchanges through the "hoa", were investigated to provide a more comprehensive understanding of processes driving temperature dynamics. Additionally, CTDs (conductivity, temperature, depth) profiles were conducted to observe temperature stratification across the three basins. Every data collection underwent quality verification, post-processing, and conversion to NetCDF format.