There is provided mechanisms for load balancing data traffic between at least two carriers in a communications network supporting the at least two carriers. A method is performed by a system. The method comprises obtaining current channel quality information for a wireless device of the at least two carriers. The method comprises predicting a future volume of a data flow of the wireless device. The method comprises determining whether to offload the wireless device to a second carrier of the at least two carriers or not according to the current channel quality information and the predicted future volume.