The distinctive morphology and novel properties of graphene is quite fascinating as a promising candidate for nanodevices. In this study, we annealed graphene oxide (GO) created through the conventional Hummers method at different temperatures, showcasing the simplicity, safety, and cost-effectiveness of thermal annealing as a superior large-scale fabrication approach. GO's capacity for post-thermal modification broadens its versatile applications in optoelectronics, electronics, nanoelectronics, and more. In this regard, this study investigates the optical, electrical properties, and chemical structure of GO after thermal reduction at temperatures 80°C, 120°C, 160°C, 200°C, 240°C, and 280°C under standard atmospheric pressure. According to the results of the Raman AFM map, the most obvious changes in thickness were observed at 280°C, where the average thickness of the reduced GO decreased by 50%. IR spectra indicated that the oxygen-containing functional groups are most stable up to 120°C and showed the loss of signals from hydroxyl groups at all other treatment temperatures. The values of the electrical sheet resistance after thermal reduction decreased from 2831.2 to 20.8 MΩ/square, which, in turn, affected the decrease in the interplanar distance from 7.12 Å to 3.80 Å. This work demonstrates a novel and effective strategy for fabricating high-performance, rGO films from local raw materials.