Sea fog is a major hazardous weather phenomenon that threatens the safety of ship navigation and port operations in the Yellow Sea waters. In this study, we use multiple observational datasets and the Weather Research and Forecasting (WRF) model to investigate the impacts of spring and summer Sea Surface Temperature (SST) cold patches on the distribution of the Yellow Sea fog. Based on 71 years of shipboard observations, we find that the occurrence frequency of the Yellow Sea fog in cold patch areas, including the waters near Qingdao, Chengshantou and the Subei Shoal, is approximately 10% higher than the basin-averaged fog frequency in spring and summer. Comparison between SST datasets of different resolutions and buoy observations shows that the Group for High-Resolution Sea Surface Temperature (GHRSST) dataset has the smallest underestimation of cold patch intensity. We further develop a cold patch removal scheme, and conduct the control experiment and no-cold-patch experiment by taking the original GHRSST and the cold-patch-removed GHRSST as the lower boundary conditions, respectively. The Lin microphysics scheme, which delivers superior performance in sea fog forecasting, is adopted to perform hindcasts of the Yellow Sea fog from April to July during 2014 to 2016. Comparison results between the two experiments show that cold patches enhance atmospheric stability by increasing the air-sea temperature difference near the sea surface, thus forming a stable stratification conducive to the formation and maintenance of the Yellow Sea fog. Over the cold patches, relative humidity increases, wind speed decreases, and liquid water content is significantly higher, leading to an approximately 15% increase in the multi-year averaged fog frequency. Further comparison between the two sets of hindcast experiments reveals that cold patches cause a significant rise in the false alarm rate of the Yellow Sea fog. This indicates that merely improving the SST resolution of the lower boundary conditions and enhancing cold patches cannot significantly improve the forecast skill for the Yellow Sea fog.