Wheat grain yield is limited due to terminal heat stress. Inconsistency of the previous results reflects the interactions between genotypes and environments. In North West Plain Zone (NWPZ), where the hot, dry wind is frequent during grain filling, wheat cultivars suffer from loss of grain weight because of low grain filling rate. A field study was carried out under late sown conditions in NWPZ to evaluate the phenological variations using heat-accumulated system and its relation with yield in twenty five wheat genotypes. Grain yield was positively correlated with days to heading, biological yield, harvest index and grain number per spike in both timely (TS) and late sown (LS) varieties, while grain weight and flag leaf area also showed positive correlation with grain yield in LS varieties. Grain growth rate (GGR) at 14 and 28 days after anthesis (DAA) showed positive correlations with grain weight in TS, and in LS genotypes flag leaf area was positively correlated with GGR at 14 DAA. Increasing days to heading resulted in higher grain yield, while increasing grain filling duration has little effect. PBW 343 and WH 711 in TS varieties and WH 1022 and PBW 373 in LS group had highest grain yields in their respective groups among the genotypes studied. These genotypes tended to have relatively longer pre-heading periods with medium maturity. The results of this study indicate that NWPZ adapted cultivars would have long pre-heading periods, moderate grain filling duration, high grain filling rates and mature early to avoid late-season drought and high-temperature stresses to attain high yields. Therefore, high yielding wheat cultivars adapted to subtropical environments can be develop by selecting the genotypes with medium maturity and a relatively long time to heading.