The stable isotope composition of meteoric water has been widely used to understand hydrological processes worldwide. We present a unique dataset, with the isotopic composition (δ¹⁸O and δ²H) of meteoric waters, derived from a nationwide study in Cuba. It includes monthly composite and event-based precipitations, from January 2017 to December 2021 (N = 526 and N = 111 respectively). Monthly data showed minor seasonal trends (dry vs. rainy), with a notable influence of tropical cyclones. Event-based data demonstrated that precipitation associated with tropical cyclones exhibited lower isotopic compositions. The analysis of potential factors influencing the isotopic composition of precipitation showed a minor influence of the rainfall amount, but negligible influence of factors such are relative humidity, elevation, and air temperature. This data set can be used as a tool not only to understand hydrological processes at the country scale, but also to further improve and develop isotope-enabled modelling for assessing water balances and fluxes, understanding the impact of extreme events, and paleoreconstruction in the Intra-Americas Sea.

Tracer hydrology in Latin America and the Caribbean has made significant progress in recent decades, largely through the sustained support of the International Atomic Energy Agency (IAEA). Current practises show water stable isotope applications and precipitation‐groundwater monitoring at the core of most networks, providing valuable insights into recharge mechanisms, groundwater to surface water connectivity, pollution tracking, and climate variability. Despite these advances, critical challenges persist, including short and fragmented monitoring records, limited capture of extreme events, restricted data accessibility, and persistent barriers related to funding, analytical capacity, and weak policy integration. Improving science communication emerges as an urgent need to transform technical findings into actionable knowledge that informs decision‐makers and empowers communities. Opportunities exist to build on IAEA's legacy by sustaining long‐term networks, diversifying tracer applications, mobilising citizen science in monitoring efforts, expanding modelling and laboratory capacity, and advocating for FAIR data sharing across end‐users. Strengthened collaboration across the region, improved communication, and deeper policy engagement can elevate tracer hydrology into a pillar of regional water governance and hydro‐climate resilience.

Small Island Developing States (SIDS)1 face significant challenges in managing their water resources, a situation that is being exacerbated by impacts of climate change on water catchments and wate...