Thermally modified wood has an increasing interest in exteriors due to its longer service life and attractive appearance. This work evaluates the influence of the thermal modification cycle on the physical properties of ayous wood (Triplochiton scleroxylon K. Schum). Ayous planks were dried and then thermally treated for 6 hours in a conventional oven at 180°C, 190°C, and 215°C. The samples obtained were characterised for density, basic density, shrinkage and shrinkage anisotropy coefficient, and colour. Data were collected in accordance with the UNI ISO reference standards. The results of this study showed that wood density decreased by 10%, 14%, and 20%; the basic density decreased by 10%, 18%, and 22%; the tangential shrinkage decreased by 17%,29%, and 53%; the radial shrinkage decreased by 6%, 14%, and 50%; and the volumetric shrinkage decreased by 13%, 51%, and 80%; these values are referred, respectively, to 180°C, 190°C, and 215°C modification cycles. Thermo treatment is confirmed an interesting process to enhance wood stability in outdoor use.