Delamination is a predominant failure mode in continuous fiber-reinforced laminated composite structures. Based on the location and direction of growth, there are two distinct types of delamination, namely, free edge delamination and local or transverse crack tip delamination. In many cases, both types occur concurrently with varying levels of interaction. In this paper, a shear deformation model including hygrothermal effects is developed for the analysis of local delaminations originating from transverse cracks in 90° plies located in and around the laminate midplane. A sublaminate approach is used and the model is applied to (±25/90n)s T300/934 graphite/epoxy laminates for n values between 0.5 and 8, along with previously developed edge delamination shear deformation models. Critical loads and delamination modes are identified and compared with experimental results. Hygrothermal effects are included in all the models to make the comparisons realistic.