Abstract: A wireless phone navigation system that obtains and uses weather system data to alert and re-route a user around inclement weather located at a point on the user's navigated route, as predicted to be at a time in the future that the user would otherwise be expected to traverse that part of the navigated route. A weather polygon is drawn around a perimeter of a weather system obtained from current weather data. The weather polygon (or other shape) may be drawn based on configurable weather items to be avoided, e.g., rain, ice conditions, snow on ground, etc. The re-routing may be based on a prediction of a future position of a weather system with respect to where on a navigated route a user will be at that future time.