Crosswind is a big challenge to the cooling performance of natural draft dry cooling towers (NDDCTs) and has attracted a lot of attention in previous research. This study proposed a new method to increase the performance of NDDCT under crosswind conditions by optimizing the hot water mass flow rate in the air-cooled heat exchangers. The 20 m UQ Gatton NDDCT was selected as a case study to test and validate this method. The cooling performance of this cooling tower under crosswind condition was evaluated by the 3-D CFD model. The results show that the crosswind redistributes the air flow and result in a non-uniform heat exchanger performance. By optimizing the hot water mass flow rate among the heat exchanger bundles, the cold fluids and hot fluids of the air-cooled heat exchanger can be better matched. The cooling performance of the NDDCT is increased by 18% when the crosswind speed is 4 m/s. (C) 2016 Elsevier Ltd. All rights reserved.