The aim of this study was to investigate the impact of rainy season in open cast mining and possible factors that could contribute to production loses during these rainy periods. The major issue at Wescoal’s Khanyisa Colliery is the impact that rainfall has on the coal extraction process during the rainy season. The opencast mine operation loses a significant amount of time that is supposed to be used to run the mining value chain by trying to deal with the effects of the rainfall. This study made use of acquired data from Khanyisa Colliery between the period of December 2019 and January 2020 rainy months in South Africa. This data includes, the amount of daily and weekly rainfall, the water pumping rate, frequency of breakdowns and success rate of load and haul. The average weekly rainfall was found to be 69 mm over the 8 weeks of the summer season. However, the adopted method of managing the mine water was not efficient enough as a result of a low capacity pump and their pumping rate in comparison to the volume of water in the pit. This has affected some sections in the mine as productivity dropped due to reduction in loading and hauling activities from the pit to the stockpiles. In order to improve the productivity, the authors made some suggestions than can enhance production during rainy seasons.