Abstract <p>This study presents a comprehensive investigation into the hygrothermoelastic behavior of orthotropic materials, focusing on the intricate coupling between moisture diffusion, temperature variation, and mechanical stresses. The generalized equations of hygrothermoelasticity are utilized to derive a three-dimensional (3D) model, which is subsequently reduced to a two-dimensional (2D) framework for analyzing plane wave propagation in an elastic medium. The primary physical fields under consideration (elastic displacements, temperature, and moisture diffusion) are coupled through the governing equations and are influenced by mechanical and thermal sources applied at the material’s free surface. Wave solutions are utilized to solve the coupled wave equations that are produced in terms of moisture content, displacement, and temperature. A mechanical and thermal source is applied over the free surface of the hygrothermoelastic media to acquire the components of displacement, stresses, temperature field, and moisture concentration in the medium. These components are then graphically depicted. The results reveal significant insights into the role of moisture content in altering wave propagation characteristics, including changes in wave speed, amplitude, and attenuation. These findings underscore the critical influence of moisture on material properties such as stiffness, strength, and thermal conductivity. Furthermore, the study highlights the interdependence of thermal and mechanical fields, demonstrating the complex interactions between environmental factors and orthotropic material behavior.</p>