This paper examines and compares smallholder farmers’ perceptions of climate change with the collected meteorological data (1980–2015) across the seven agroecological zones (AEZs) of Tanzania. Systematic and simple random sampling procedures were employed in the selection of districts and villages, respectively. This study used both quantitative and qualitative datasets. Quantitative data were derived from climatic records and questionnaires, while the qualitative data were widely derived from interviews and discussions. The Mann–Kendall test (software) and theme content (method) were used for data analyses. The results showed that rain has experienced a significant change in terms of patterns, frequency, and intensity, while temperature was locally increasing in all the AEZs. Moreover, the farmers’ responses to both closed and open questions indicated that most of them (.70%) noticed these alterations. Comparatively, the farmers residing in the most vulnerable AEZs, that is, arid and semiarid lands, were more responsive and sensitive to climatic impacts than those in the least vulnerable zones, such as alluvial regions. The increase in temperature and change in the rain patterns led to the decrease in crop yields. As a response to this, farmers have adopted new strategies such as early planting and the use of shorter growing crops cultivars. This study concludes that, although farmers’ perceptions were correct and echoed the meteorological/measured data in all the AEZs, adaptation and mitigation strategies are inadequate.