In this paper, we deal with the ARIMA (Box-Jenkins) model of the gridded mean annual air temperature for the area included by the co-ordinates: 20°- 30°E, 35°- 45°N, (thus the South Balkan area, the most of its percentage covered by Greek peninsula). We analyse the gridded temperature time series which existed from 1851 to 1996. With the theoretical model's construction, we try to forecast the annual temperature till the year 2006, and the results were satisfactory enough. Also, from the analysis we found that the autocorrelation function (ASF) and the partial autocorrelation function (PASF) of the residuals were not significant, and the ARIMA model is quite reliable.