Among the primary contributors to airplane performance degradation over time is the accumulation of precipitation on the wing surface. For this reason, a direct relationship was determined between the absolute pressure around the airfoil and a dimensionless variable that can characterize the effective accumulation of precipitation on the wing - i.e. the precipitation collection efficiency. The precipitation collection efficiency was obtained for the NACA 0012 airfoil at various wind angles of attack ranging from 0 degrees to the stall angle of 16 degrees. This allowed for the observation of effects of wind angle of attack on wing precipitation accumulation. In addition, the effects of absolute pressure and velocity on precipitation accumulation were observed for all tested angles of attack. The minimum absolute pressure magnitude around the airfoil was discovered to have an inverse relationship with the wind angle of attack. In turn, precipitation collection efficiency was found to have an inverse relationship to the absolute pressure magnitude. The velocity field around the airfoil for every wind angle of attack showed that the precipitation collection coefficient was highest in the region with the lowest absolute pressure, indicating that the precipitation essentially flows with the air to a region of lower absolute pressure. Through a series of equations involving the Langmuir-Blodgett modified water droplet inertia parameter, a direct method for calculating precipitation collection efficiency from air absolute pressure was developed, thereby allowing future experiments on airfoil precipitation accumulation to have a theoretical check.