A real-time video dehazing algorithm, which reduces flickering artifacts and yields high quality output videos, is proposed in this work. Assuming that a scene point yields highly correlated transmission values between adjacent image frames, we develop the temporal coherence cost. Then, we add the temporal coherence cost to the contrast cost and the truncation loss cost to define the overall cost function. By minimizing the overall cost function, we obtain the optimal transmission. Moreover, to reduce the computational complexity and facilitate real-time applications, we approximate the conventional edge preserving filter by the overlapped block filter. Experimental results demonstrate that the proposed algorithm is sufficiently fast for real-time applications and effectively removes haze and flickering artifacts.