Thin rainwater lenses are an essential water resource for agricultural areas in coastal regions, as they support crop growth by giving access to fresh water. They are formed when the upward movement of saline groundwater (seepage) prevents rainwater from infiltrating to greater depths. It is unknown how the disappearance of thin rainwater lenses will be exacerbated by more frequent (multi-year) droughts due to climate change. This study investigated the future viability of rainwater lenses and explored the conditions that enhance climate resilience in diverse spatial environments. We developed a numerical model using SEAWAT to investigate rainwater lens dynamics and the impact of droughts on their viability. An extensive sensitivity analysis was conducted with varied climatological and environmental conditions, based on the Southwest Delta in the Netherlands, a region with over 600 km² of brackish to saline groundwater within 5 meters of the surface. Climate scenarios from the Dutch meteorological institute were used, that align with SSP pathways (SSP1-2.6, SSP2-4.5, and SSP5-8.5). Our results demonstrate that thin rainwater lenses are less viable under future climate conditions. It emphasizes the importance of climate signals in determining rainwater lens viability alongside physical parameters such as tile-drainage configuration (drain levels and distance), seepage fluxes, and soil types. While thicker rainwater lenses are expected with wetter winter conditions, severe recharge deficits, particularly in late summer and early autumn, extend periods of rainwater lens absence. Under median conditions, soils with coarser textures, lower seepage rates, and deeper, more intensive drainage systems show reduced sensitivity to rainwater lens absence, enhancing climate resilience. Conversely, areas with elevated drainage levels, increased seepage rates, finer-textured soils, and greater drainage distances show heightened sensitivity. Dry-trending scenarios lead to extended periods without rainwater lenses while wet-trending scenarios limit the reduction in fresh drainwater volumes.