The changes in air temperature with the land use / land cover (LU/LC) in the certain areas highly affect to the environment and its ecosystem. This study aims to evaluate LU/LC changes and their impacts on climate in Hambantota Divisional Secretariat Division from 2008 to 2019. Both LU/LC cover changes were determined by using supervised classification, particularly maximum likelihood classification and accuracy assessment in Remote Sensing and GIS techniques. Spatial distribution of air temperature is determined by Inverse Distance Weighting (IDW) method by assigning values to unknown points are calculated with a weighted average of the values available at the known points. The results found that the increment of built-up areas (27.66%), water bodies (2.39%) and agriculture (0.44%) and decrement of barren lands (11.61%) and forest cover (18.88%) having accuracy ranged from 86.7 percent to 83.3 percent with 0.888 to 0.912 Kappa statistics. These changes are further confirmed by the Normalized Different Vegetation Index (NDVI). Moreover, the increment of air temperature is detected during 11 years. This air temperature increment is proportional to the forest cover reduction and the buildup area increment due to vast developments in the area after 2009.