The effect of freeze-thaw weathering on the tensile properties, and accelerated weathering with xenon-arc light on the color stability and the tensile properties of co-extruded wood–polypropylene composite loaded with different carbon fillers, such as carbon black, graphite, expandable graphite, carbon nanotubes, and carbon fibers is studied. The results showed that carbon fillers prevented the composites from the fading during xenon-arc light weathering. Almost all types of composites showed the reduced tensile properties after the weathering so that during xenon-light treatment, the tensile strength decline for 10–22% and modulus for 9–25%; during freeze-thaw cycling reduction was 3–21% for the strength and 4–20% for the modulus. Scanning electron microscopy analysis revealed deterioration of the polymer surface layer in all xenon-light weathered composites.