Hydrogen, as a renewable and clean energy carrier, has the potential to play an important role in carbon reduction. Crucial to achieving this is the ability to produce clean sources of hydrogen and to store hydrogen safely. With the rapid development of the hydrogen industry, the number of hydrogen refueling stations (HRS) is increasing. However, hydrogen safety at HRS is of great concern due to the high risk of hydrogen leakage during storage. This study focused on an integrated hydrogen production and refueling station (IHPRS) in Weifang, China, and numerically simulated a hydrogen leakage accident in its storage area. The effects of the leakage aperture, the leakage direction and the ambient wind direction and speed on the leakage and dissipation characteristics of hydrogen were investigated. The results showed that the volume, mass and dissipation time of the flammable hydrogen cloud (FHC) increased with an increase in the leakage aperture. The installation of a canopy or densely packed equipment near the hydrogen storage area will seriously hinder the dissipation of the FHC. Ambient winds in the opposite direction of the leakage may cause high-concentration hydrogen to accumulate near the hydrogen storage tanks and be difficult to dissipate, seriously threatening the safety of the integrated station.