Soil moisture (SM) is a critical water cycle component, affecting infiltration, runoff generation, and flood risks. In the Mediterranean region, rising temperatures and decreasing precipitation alter SM distribution, contributing to a declining trend. Intensifying rain events driven by climate change further challenge SM’s flood regulation role. Therefore, accurate SM assessments are essential for understanding these dynamics. However, the scarcity of in-situ measurements necessitates reliance on satellite-based data, which offer global coverage but involve uncertainties. This study aims to evaluate the accuracy of satellite-based SM data in the Mediterranean and explore SM dynamics under climate change. SM data from NASA’s Soil Moisture Active Passive (SMAP) mission was qualitatively analyzed using hydrometeorological data, including rainfall and streamflow from the Yarkon-Ayalon basin in Israel. Due to the lack of in-situ data in Israel, SMAP data was quantitatively assessed against in-situ SM measurements from the REMEDHUS network in Spain. The methodology included data preprocessing, quality control, spatiotemporal averaging, pixel-based and spatial average comparisons, and time-series analyses to assess SMAP accuracy at event and seasonal scales. Results indicate that SMAP captures general SM dynamics observed in the REMEDHUS network, though accuracy varies across stations and seasons. Spatial averaging reduces these errors and improves data reliability. Comparisons with rainfall and streamflow data in the Yarkon-Ayalon basin reveal consistent dynamics, underscoring SMAP’s utility in capturing hydrological responses to rainfall events and seasonal variations. Based on these findings, further analysis will examine extreme SM events across various Mediterranean basins, identify their meteorological and hydrological drivers, and analyze SM trends concerning climate change. These insights will improve understanding of SM dynamics, enhance SM predictions under climate change, and support flood risk and water resource management in the Mediterranean.