The major geographic feature that influences weather patterns in Italy is the Appennine Mountains. This mountain range runs the length of Italy, acting as a climatic divide that affects precipitation and temperature distribution across the country. The presence of these mountains contributes to regional climatic variations, with the western side typically experiencing wetter conditions compared to the eastern side, which may be drier. Additionally, the Appennines play a vital role in shaping local ecosystems and agricultural practices, influencing which crops can be cultivated in various regions. Their geological significance is essential for understanding Italy's diverse landscapes.