Bisphenol A polycarbonate (PC), a lightweight and impact-resistant glass substitute widely used in structural and optical applications, suffers from hydrolytic degradation under heat and humidity, limiting its long-term outdoor reliability. In this study, the hydrolysis of PC under neutral and acetic acid conditions was systematically investigated via accelerated aging at a controlled temperature, humidity, and acetic acid concentration. Mechanical degradation was assessed by tensile testing, whereas molecular-weight evolution was evaluated using gel permeation chromatography (GPC) to establish kinetic parameters. The hydrolysis process was modeled according to first-order kinetics, justified by comparison with alternative rate laws and supported by high linearity. Activation energies and pre-exponential factors were extracted from Arrhenius analysis. The results reveal that exposure to 10% v/v acetic acid at 60°C induces a 48.6% reduction in maximum tensile strength after 1000 h, correlating with a pronounced decrease in molecular weight. Contrary to catalytic expectations, acetic acid increases the apparent activation energy, suggesting that it stabilizes the reactant relative to the transition state. Complementary differential scanning calorimetry (DSC) confirmed a decrease in glass transition temperature with molecular-weight loss, consistent with the Flory–Fox relation. Degradation products identified by MALDI-TOF were consistent with the formation of bisphenol A, phenol, and isopropenylphenol (IPP). These results provide a quantitative framework for understanding acid-assisted hydrolysis in PC and offer predictive insight for its long-term mechanical reliability in humid or acidic environments.