Contrasting Temperature and Precipitation Responses to Climate Change at a Central Adriatic Coastal Station: A Multi-Timescale Analysis of Split–Marjan, Croatia

This station-scale study examines contrasting temperature and precipitation responses to climate change at Split–Marjan, Croatia, using daily observations (1948–2025) and hourly observations (1996–2025). Long-term trends, change points, temperature and precipitation extremes, compound events and conditional precipitation–temperature relationships were analysed. Annual mean air temperature increased by 0.581 °C decade−1 (p < 0.001) during 1996–2025, accompanied by increasingly frequent warm extremes and heatwaves. In contrast, annual precipitation totals showed no significant long-term trend, although daily and hourly observations revealed changes in precipitation frequency and intensity. Mean wet-hour precipitation intensity increased, while the relative contribution of the most intense wet hours decreased. Annual maximum precipitation accumulated over durations of 1–24 h exhibited no statistically significant trends. Compound conditions showed a pronounced increase in warm–dry days (+11.36 days decade−1, p < 0.001) and a decrease in cold–dry days (−10.00 days decade−1, p < 0.001). Heavy hourly precipitation exhibited nonlinear temperature scaling, with a dataset-specific empirical breakpoint at approximately 21 °C, below which conditional intensity increased with temperature and above which it decreased. Overall, the findings demonstrate pronounced warming accompanied by heterogeneous precipitation responses, emphasizing changes in the thermal characteristics of dry conditions and providing an observational basis for future investigations of climate-related impacts on coastal water resources.