The Balkans are located in south east Europe. A new data set of high quality homogenized daily maximum and minimum summer air temperature series from 246 stations in the eastern Mediterranean region (including Albania, Bosnia-Herzegovina, Bulgaria, Croatia, Cyprus, Greece, Israel, Romania, Serbia, Slovenia, Turkey) has been developed and used to quantify changes in heat length and intensity between 1960 and 2006. Daily temperature analyses suggest that many instrumental measurements in the 1960s are warm biased, correcting for these biases regionally averaged heat wave trends are up to 8% higher.