From the climatological point of view, northeast Iberia is an area of large interest due its varied geographical, topographical and climatic characteristics. This work provides a comprehensive assessment of observed changes of the surface air temperature in NE Iberia, using a a long, reliable and complete temperature data set. This work also investigates the spatial and temporal characteristics of extreme temperature events by using a set of 21 climate indices. In addition, this study explores the forcing mechanisms that explain temperature variations in the region, including the large-scale atmospheric patterns (e.g., NAO, EA, SCA, and WeMO). Finally, this work assesses future changes in temperature mean and extremes using a set of regional climate models (RCMs). Assessing and attributing temperature variability in NE Iberia is important for extracting finer scale information, which may prove useful for the vulnerability assessments and the development of local adaptation strategies for various disciplines, such as hydrology, agriculture, water resources management, ecology and human health.