This paper identifies the trends and the magnitudes of change in climate indices in the Eastern Anatolian region of Turkey during 1965-2015 by using monthly data from 25 stations, including mean air temperature, rainfall, maximum snow depth, snow days, duration of snow covered ground, relative humidity and wind speed by considering the altitudinal factors (A1 <= 1500m, A2 > 1500m zones). The procedure utilizes the Mann-Kendall non-parametric test to determine statistically significant (p<0.05) trends, Sen's slope estimator to detect the magnitude of the change and the Pearson's coefficient to measure the correlation of climate indices. The application of the trend detection technique to temperature has yielded the identification of significant increasing trends for most of the region with the average magnitude of 2.02, 1.63, 1.44 and 0.75 degrees C during a period of 51 years for the winter, spring, summer and autumn seasons respectively. However, almost no evidence of significant change was experienced despite a decrease in the rainfall. For the snow days, the duration of snow covered ground and maximum snow depth were statistically decreased by 13.75 days, 14.41 days and 16 cm during the 51 year period for the winter. Furthermore, the relative humidity and wind speed data reflected an overall decreasing trend observed for each season. The correlation analysis of the climate indices has indicated that there is a high negative relationship between the mean temperature and snow indices for both altitude zones (higher in the lower). Sites located at lower altitudes differ from those at higher elevations for rainfall and temperature correlations, where at lower altitudes; colder years tend to be wetter. The significant negative correlation between relative humidity and temperature has been revealed, as expected, in both altitude zones due to the limited water supplies in the current study area. The trends of climate indices reflect the active role undertaken by climate change in the region revealing an evident relationship between altitude and climate change. Consequently, we attempted to introduce the magnitude of climate change for its use in the mitigation and future adaptations in further studies.