Stay cables of the cable-stayed bridge exhibits a large amplitude vibration under the action of wind and rain and which may have a greater effect on the fatigue life of the stays. These large amplitude vibrations were strongly influenced by variety of factors concerning the positioning of the cable (inclination angle), meteorological parameters (rain, wind speed and wind direction) and the structural parameters like damping and frequency. This paper explains the effects of wind speed, rainfall, damping, cable diameter, cable inclination angles, wind yaw angles on the vibration amplitude of the stay cables with diameters 0.155 m and 0.128 m. The observations show's large amplitude vibrations when the cable is inclined at 25° and 30° and wind yaw angles are from 30° and 35° under 10 mm/hr rainfall condition.