Gas exchange at air-water interfaces is regulated by near-surface turbulence and can be controlled by different atmospheric forcing conditions, with wind speed and surface buoyancy flux being the most recognized drivers in empirical studies and modeling approaches. The effect of rainfall on near-surface turbulence has rarely been studied and a consistent relationship between rain rate and near-surface turbulence has not yet been established. In this study, we explore the influence of rain on near-surface turbulence and gas transfer velocities over a wide range of rain rates (7 to 90 mm h^-1) under laboratory conditions, using particle image velocimetry measurements and dissolved oxygen as a gas tracer. The rain-induced dissipation rates of turbulent kinetic energy declined with depth following a consistent power-law relationship. Both energy dissipation rates and gas transfer velocity increased systematically with the rainfall rate. The results confirm the causal relationships between rainfall, turbulence, and gas exchange. In addition, we propose a power-law relationship between near-surface turbulent dissipation rates and rain rate. In combination with surface renewal theory, we derived a direct relationship between gas transfer velocity and rain rate, which can be used to assess the importance of short-term drivers, such as rain events, on gas dynamics and biogeochemical cycling in aquatic ecosystems.