Ethiopia is a home for a number of food crop varieties suited to the dry and high temperature conditions. It varies from Denakil Desert to cool wet alpine highlands in climate variability. The vigorous indigenous crops were growing in a diversified manner in their agroecological suitable area across Ethiopia as well as Gumara watershed. But starting from some years back, the diversely growing of those crops are affected by climate variability. The study area is one of the richest areas in indigenous crop types and faced with the aforementioned problem. Thus, the study aimed to analyse the trend of climate and the decadal dynamics of the crop diversity in the watershed. The Gridded Satellite and observed historical climate data from 1987-2016 period and crop-climate history were the data sources. Using the MannKendall test and Sen’s Slopes estimator, for trend, rating of Food and Agriculture Organization crop-climate requirement, for crop diversity dynamics were employed methods of data analysis respectively. The result indicated non-significantly increasing of decadal Kiremit rainfall in 27mm at Weyna Dega and 43mm at Dega agroecological zones. The kiremit season temperature variables are in a statistically significant increasing trends at all zones. In general, 0.4 o c of decadal increments of minimum and maximum and 0.5 c of mean temperature increment is recorded in the watershed. The recent period of decadal increment in maximum temperature negatively affecting most selected indigenous crops at the lower elevation and helps to move the crops forward to the higher elevation. The local farmers perception results agreed with the historical climate data analysis. Improved crop verities shall be introduced to the watershed agroecological zones. The traditional agroecological zone classification system of Ethiopia must be systematically updated. In order to detect the detail information on crop-climate associations/ effects of climate variability on crop diversity, the yearly analysis rather than decadal analysis; shall be suggested respectively for governments and future researches.