In this study, changes in some physical properties after accelerated weathering of Thermowood Wild Cherry (Cerasus avium (L.) Monench) wood were investigated. Firstly, Wild Cherry (Cerasus avium (L.) Monench) planks were heat treated by Thermowood method and Thermowood Wild Cherry was obtained. Afterwards, the trial samples prepared were periodically accelerated with 144, 248, 576 and 864 hours of UVB lamps, and color values (L, a, b and ∆E) and average surface roughness (Ra) values were determined at the end of each period. The results were analyzed by multiple comparison techniques with SPSS and Duncan test was applied to see if there were p <0.05 statistical differences. The results of the study showed that the average surface roughness values were better in Thermowood samples than the control samples. On the other hand, it has been determined that the samples darkening with heat treatment have started to gray on the surfaces with aging, and the degree of graying increases due to the prolongation of the weathering period.