Genetic stability and diversity are two of the key factors for the improvement of many crop plants. A major challenge for plant breeders is selection of high yielding genotype with wide adaptation. Therefore, thirty six wheat genotypes were evaluated under two locations (Sohag and Aswan, Egypt) on favorable and late sowing date during winter seasons of 2012/2013 and 2013/2014 to estimate its performance and stability parameters. The wide range of weather conditions resulted in a broad variation of mean yields, ranging from 6.59 t/ha in favorable sowing date to 4.99 t/ha in late sowing date as heat stress. The combined analysis of variance showed that the flag leaf area, days to heading, spike length, 1000-kernel weight and grain yield were significantly influenced by years, locations, sowing dates and genotypes. Mean environmental grain yield ranged from 2.70 t/ha to 9.27 t/ha. The results showed that sowing at the favorable date increased all studied traits. The 36 genotypes showed diversity for the slopes of the joint regression. Genotypes No. 5, 6, 14, 19, 20, 22, 24 and 32 exhibited stability for grain yield and useful in the breeding program in developing new wheat genotypes with tolerance to heat stress conditions. Positive correlation was found between b_i and  for days to heading, spike length, number of kernels/spike, 1000-kernel weight and grain yield (0.89**, 0.50**, 0.07, 0.13 and 0.51**), respectively. This might be due to adaptation of these genotypes to wide differences in climatic conditions which prevailed at the two studied locations. The best genotypes in terms of both favorable and heat stress indicating that selecting for improved yield potential may increase yield in wide range of environments.