Friction stir welding (FSW) is a widely employed welding process, in which advancing and rotational speeds consitute critical parameters shaping the welding outcome and affecting the temperature evolution. This work develops an experimental methodology to identify optimal FSW parameters based on real-time temperature measurement via a thermocouple integrated within the tool. Different rotational and welding speeds were tested on AA5083-H111 and AA6082-T6. Our results underscore the importance of attaining a minimum temperature threshold, specifically 0.65 times the solidus temperature, to ensure high-quality welds are reached. The latter are defined by combining temperature measurements with joint quality information obtained from cross-sectional views. Our research contributes to advancing the efficiency and effectiveness of friction stir welding in industrial settings. Furthermore, our findings suggest broad implications for the manufacturing industry, offering practical insights for enhancing weld quality and process optimization.