Ocean water turbidity, influenced by marine chlorophyll concentration, significantly alters the distribution of shortwave radiation in the water column. This work aims to assess the effects of turbidity on the upper-ocean physical properties and their subsequent impact on the atmosphere, using a coupled ocean-atmosphere regional model for the Mediterranean and Black Seas. We performed 11-year (2011-2021) twin-simulation experiments, based on different chlorophyll concentrations to estimate turbidity and the penetration of solar radiation in the ocean. The first simulation used a monthly climatology field of chlorophyll concentrations derived from satellite observations, whilst in the second experiment, the chlorophyll concentration was kept constant at 0.05 mg m−3, representing clear water turbidity conditions. Results show that radiative heating driven by ocean turbidity amplifies the seasonal cycle of temperature in the upper layers, leading to increased surface warming in summer and surface cooling in winter. Also, higher turbidity contributes to cooling in subsurface layers throughout the year due to its shading effect. The temperature response to turbidity in the water column is controlled by the mixed layer depth and a balance between (1) direct near-surface radiative heating due to chlorophyll solar absorption, and (2) indirect cooling resulting from vertical turbulent mixing processes with subsurface waters. The atmosphere moderates the seasonal sea surface temperature (SST) response to turbidity, primarily through changes in latent heat flux. Ultimately, our simulations suggest that increased turbidity enhances the Mediterranean overturning circulation, highlighting the necessity of incorporating realistic turbidity forcing into regional climate modeling studies.