The study by Liebminger et al. (2007) investigates the isotopic composition of groundwater and precipitation in Austria, focusing on the role of climate and local meteorological parameters. The authors highlight that the isotopic signature of meteoric water, primarily determined by Rayleigh processes during precipitation formation, is a key tracer in hydrology and paleoclimatology. However, the variability in the isotopic ratio of oxygen-18 to oxygen-16 (δ18O) in precipitation and groundwater cannot be fully explained by temperature alone. The study demonstrates that interactions between different climate-induced changes in local parameters, such as relative humidity and the type of precipitation, play a significant role in explaining the observed deviations from temperature-based predictions. The research uses a unique dataset of nearly 30 years of monthly Vienna drinking water samples and isotopic precipitation data from the Wildalpen recharge area. The results show that temperature explains 27% to 32% of the variance in δ18O patterns, while other factors like relative humidity, the snow-to-precipitation ratio (S/P), and the North Atlantic Oscillation (NAO) index also contribute significantly. The S/P ratio, which is sensitive to climate variability, correlates strongly with δ18O, indicating that changes in the ratio influence the final composition of precipitation due to non-equilibrium fractionation during sub-cloud evaporation processes. The study also examines the impact of local meteorological conditions on δ18O variations, using examples from different locations in Austria. It finds that the δ18O trends at these sites cannot be fully explained by temperature alone, suggesting that sub-cloud evaporation and relative humidity are important factors. The authors conclude that the isotopic composition of meteoric water reflects not only temperature but also other local meteorological parameters, providing valuable climate information for (paleo)climatic applications.The study by Liebminger et al. (2007) investigates the isotopic composition of groundwater and precipitation in Austria, focusing on the role of climate and local meteorological parameters. The authors highlight that the isotopic signature of meteoric water, primarily determined by Rayleigh processes during precipitation formation, is a key tracer in hydrology and paleoclimatology. However, the variability in the isotopic ratio of oxygen-18 to oxygen-16 (δ18O) in precipitation and groundwater cannot be fully explained by temperature alone. The study demonstrates that interactions between different climate-induced changes in local parameters, such as relative humidity and the type of precipitation, play a significant role in explaining the observed deviations from temperature-based predictions. The research uses a unique dataset of nearly 30 years of monthly Vienna drinking water samples and isotopic precipitation data from the Wildalpen recharge area. The results show that temperature explains 27% to 32% of the variance in δ18O patterns, while other factors like relative humidity, the snow-to-precipitation ratio (S/P), and the North Atlantic Oscillation (NAO) index also contribute significantly. The S/P ratio, which is sensitive to climate variability, correlates strongly with δ18O, indicating that changes in the ratio influence the final composition of precipitation due to non-equilibrium fractionation during sub-cloud evaporation processes. The study also examines the impact of local meteorological conditions on δ18O variations, using examples from different locations in Austria. It finds that the δ18O trends at these sites cannot be fully explained by temperature alone, suggesting that sub-cloud evaporation and relative humidity are important factors. The authors conclude that the isotopic composition of meteoric water reflects not only temperature but also other local meteorological parameters, providing valuable climate information for (paleo)climatic applications.