The dataset presented here captures 114 uranium isotope ratio (234U/238U), expressed as δ234U, in a coral from northern Cuba, with data spanning the past 230 years. The primary objective was to analyze the variability in δ234U to evaluate freshwater fluxes and oceanographic changes in the northern Caribbean, particularly during the Little Ice Age (LIA). The highest fluctuations of ±8.1‰ are present at the end of the Little Ice Age, aligning with known climatic shifts. Elevated δ234U values reflect Mississippi River discharge, while lower values correspond to local precipitation along the Cuban coast. Annual variations of δ234U were measured using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) at the Institut of Environmental Physics Heidelberg, achieving an external precision of ±0.55‰.