Solar enhanced natural draft dry cooling tower (SENDDCT) is more efficient than natural draft dry cooling tower by utilizing solar radiation in arid region. A three-dimensional numerical model considering solar radiation effect was developed to investigate the influence olsolar radiation intensity and ambient pressure on the efficiency and thermal characteristics of SENDDCT. The numerical simulation outcomes reveal that a model with consideration of radiation results in a less air mass. This indicates that previous simulations overestimated solar energy obtained by the solar collector and underestimated the heat loss. The cooling performance is improved with a higher solar radiation intensity or ambient pressure. Air temperature and velocity increase with solar radiation intensity. Ambient pressure and solar radiation intensity have inverse effects on the changes of air temperature and velocity. Under a condition that the solar load increases but the ambient pressure decreases, the increased rate of heat transferred in the heat exchanger is not obvious. (C) 2016 Elsevier Ltd. All rights reserved.