Abstract: A navigation system integrating weather information is disclosed, which includes a weather information module for storing regional weather information indicating different weather condition levels and a threshold value corresponding to one of the weather condition levels; an electronic map database for storing map information; a positioning module for receiving a positioning signal via a global positioning system; and a navigation module for planning out a driving route based on the map information and the regional weather information to avoid any region that has a weather condition level higher than the threshold value and providing a navigation message based on the planned driving route and the received positioning signal. A navigation method applicable to a navigation system integrating weather information is also provided.