Mungbean is an important legume in arid regions that is under threat due to changing rainfall conditions and temperature fluctuations in the region. These risks can be addressed by optimizing sowing time and selecting the right mungbean cultivars. Therefore, the present study was conducted during summer seasons of 2018 and 2019 to reveal the best sowing time for mung bean genotypes. Experiment was comprised of two factors i.e., sowing dates; 1st April, 15th April, 1st May and 15th May, and genotypes, Bahawalpur-mung-2017, NIAB-mung-2016 and AZRI-mung-2006. NIAB-mung-2016 sown at 1st April during 2018 and 2019 took higher days to complete the phenological stages as well as gave higher viable pollens (79.63 and 73.40%), chlorophyll contents (50.11 and 47.04 mu g cm(2)) number of pods/plant (38.13 and 30.32), number of seed/pod (14.20 and 11.67), 1000-seed weight (53.21 g), grain yield (1856 and 1585 Kg ha(-1)), biological yield (5940 and 5335 Kg ha(-1)) and harvest index (31.45 and 28.04%). Likewise higher heat use efficiency, heat thermal unit, relative temperature depression were also recorded when mungbean was sown at 1st April during 2018 and 2019. Hence it is concluded that NIAB- mung-2016 sown at 1st April had the potential to increase mungbean productivity under arid conditions.