California seeks to increase renewable energy production in the near future, and utilizing large-scale offshore wind farms provides an alternative to sacrificing scarce land to meet this end. However, the impacts of offshore wind farms on the marine atmospheric environment should be understood before any decisions about wind farm placement are made. Using a high-resolution regional climate model supplemented by a wind farm parameterization, the authors investigated the atmospheric effects of a hypothetical offshore wind farm located in a region with sufficient wind resources near Northern California’s major metropolitan areas. The hypothetical wind farm, which uses large-scale, modern turbines, would provide electricity for more than 750,000 households in the Bay Area. The reference simulation, which reproduces the local micrometeorology accurately in comparison with observations, predicts that the hypothetical offshore wind farm would affect the near-surface atmospheric environment differently than an onshore wind farm would. Specifically, an offshore wind farm would introduce a vertical mixing mechanism that has a cooling effect on the marine boundary layer, causing a decrease in air temperature and an increase in air humidity. The additional moisture caused by the wind farm would subsequently condense into liquid water and form clouds at the top of the boundary layer. As they combine with the influence of wind farm-induced wake, these clouds would affect incoming radiative fluxes, surface energy budget, and the resulting surface turbulent fluxes in various ways.