A electrostatic spray system includes a sprayer that is configured to impart an electric charge on particles that are discharged from the sprayer. The system further includes a humidity sensor configured to sense humidity in a work area. An electrostatic controller is receives signals from the humidity sensor corresponding to the humidity in the work area. The electrostatic controller is programmed to selectively control the electrostatic charge imparted on the particles by the sprayer according to the signals received from the humidity sensor.