According to the historical records of outdoor air temperature(OAT)in a certain city and the weather fore-cast report from the observatory

an algorithm with oblivion function to predict OAT in a city was proposed.The expo-nential function was used as the oblivion function and the parameter in the function was recommended.Examinations show that the prediction model of a certain city possesses a high accuracy via comparing the predicted temperatures and measured ones.Based on this prediction model

a map-based prediction algorithm for OAT along the transporta-tion lines is set up considering the location

schedule and predicted temperatures of related cities along the transporta-tion line.An example on insulated transportation was adopted to present the OAT prediction along the transportation line.