This paper presents a numerical study of icing of a NACA2412 airfoil and the aerodynamic performance of the airfoil with ice accretion. The study analyzes the effects of liquid water content, accretion time and varying angles of attack (AoA) up to 200 on ice accretion and, consequently, on the aerodynamic coefficients of the airfoil. The free stream velocity and air temperature were kept constant in the simulations. Results revealed that the ratio of lift and drag coefficients was the highest after a short accretion time (i.e., about 20 minutes), but then it decreased significantly with accretion time. Ice accretion increased with time; its mass was the greatest at 100 of AoA. The results can be beneficial for designing blade shapes to optimize wind turbine performance during adverse weather conditions.