Abstract: On the basis of traditional GPS route planning and navigation, we present an algorithm for travel route planning merging with weather phenomena monitoring and nowcasting which affect driving safety such as the sleet fog, wind, rain and icy roads, etc.， and then illustrate the design of the logical structure of the system, the key business processes and physical deployment， finally check the effects of the algorithm through the integrated system which has been completed under Android platform. The algorithm and system not only are applied to the weather forecast and warning for shortdistance travel inside the city, but also suitable for intercity or interprovincial longdistance highway route planning, so as to effectively reduce the traffic accidents attributable to bad weather.

Key words: GPS navigation, shortest path, travel route planning, weather monitoring, severe weather alerts, driving safety