The Atlantic Multidecadal Oscillation (AMO) is a significant mode of climate variability with alternating warm and cool phases, affecting large parts of the Northern Hemisphere. The AMO has been linked to various regional climate phenomena, including North Eastern Brazilian and African Sahel rainfall, Atlantic hurricanes, and North American and European summer climate. However, the short instrumental climate record limits the confidence in these relationships. This study uses a 1400-year control simulation of the HadCM3 climate model to investigate the AMO's impact on these phenomena. The model confirms the association of the AMO with most of these regional climate impacts, suggesting that the AMO is a long-lived quasi-periodic internal mode. The results show that the model's simulated AMO patterns and their impacts on regional climates are consistent with observed patterns, enhancing the confidence in the physical basis of these relationships. The study also highlights the seasonal dependence of AMO impacts, with the best detection in summer for some regions. Overall, the findings suggest that the AMO's influence on regional climates is likely to be a persistent feature of its variability.The Atlantic Multidecadal Oscillation (AMO) is a significant mode of climate variability with alternating warm and cool phases, affecting large parts of the Northern Hemisphere. The AMO has been linked to various regional climate phenomena, including North Eastern Brazilian and African Sahel rainfall, Atlantic hurricanes, and North American and European summer climate. However, the short instrumental climate record limits the confidence in these relationships. This study uses a 1400-year control simulation of the HadCM3 climate model to investigate the AMO's impact on these phenomena. The model confirms the association of the AMO with most of these regional climate impacts, suggesting that the AMO is a long-lived quasi-periodic internal mode. The results show that the model's simulated AMO patterns and their impacts on regional climates are consistent with observed patterns, enhancing the confidence in the physical basis of these relationships. The study also highlights the seasonal dependence of AMO impacts, with the best detection in summer for some regions. Overall, the findings suggest that the AMO's influence on regional climates is likely to be a persistent feature of its variability.