Tourism is very important for the development economic sector, and it is deeply affected by climate. Ethiopia is a developing country with less income from the tourism sector in spite of favorable climatic conditions for tourism development. So, the specific objective of this study was to rank Ethiopian towns based on Tourism climate index developed by Mieczkowski (1985) with modifications to fit climatic data in GIS environment. Seven climatic variables based on monthly means were integrated into the TCI. Climate data of 112 points was collected and processed to create the images with Inverse distance weighted model. The data of each climate variable was classified using conditional statements following TCI’s rating scheme. The monthly TCI score value was extracted to the point features of 870 towns of Ethiopia. To find annual TCI monthly TCI values were added. Finally, Towns were ranked based on unique annual TC values. As a result, all the towns were grouped in 44 rank classes. The results reveal, Ethiopia has very high potential for the sustainable development of tourism as 190 towns were found in an ideal category ≥3 months per annum. This work will be useful for policymakers to plan and project sustainable development of tourism in Ethiopia.