The present article examines the nonlinear static/dynamic behavior of the functionally graded porous shell panel with variable geometrical shapes exposed to thermomechanical load. The higher-order shear deformation theory (HSDT) is employed to develop a finite element (FE)-based mathematical model. The geometric nonlinearity is incorporated using Green–Lagrange nonlinear strains (GLNS). Voigt's micromechanical model, in association with power-law (GT-I), sigmoid (GT-II) and exponential (GT-III) kinds of material grading patterns, is adopted to calculate the graded panel's effective properties. Also, even (PRT-I) and uneven (PRT-II) distributions of porosity are considered in the present work. The temperature-dependent (TD) properties are adopted in association with variable temperature fields, i.e., uniform (TD-I), linear (TD-II), and nonlinear (TD-III) for the computation of flexural responses. To compute the desired nonlinear responses, the direct iterative technique is utilized. Convergence is used to validate the established model's stability and correctness is further verified by comparing the current numerical data to published and experimental results. The experiment was carried out by fabricating a few natural fiber-reinforced linearly varying layerwise panels for the test run. The study is further extended to investigate the influence of design parameters on nonlinear static and transient data (flexural/stress) of the functionally graded curved/flat panel considering thermal environmental conditions.