Understanding divergent perceptions of ethnic groups to climate change in mountainous regions home to multi-ethnic cultures and the factors influencing these perceptions is crucial for policymakers to predict the trending impacts of climate change and make long-term decisions. Based on the case of Southwest China, 1216 households were interviewed by questionnaire surveys to gain insight into the perceptions of local people on the dynamic evolution characteristics of climate events in the uplands of Yunnan, China, which is an area home to rich ethnic diversity, and also to determine the factors that influence these perceptions. Results indicated that climate events have now become important events for farmers’ livelihoods, ranking only after family diseases and livestock diseases. Drought, long-term drought, and erratic rainfall are the three kinds of climatic events with the most significant increase in frequency and severity in mountainous areas. Farmers’ perceptions on whether drought, long-term drought, and erratic rainfall occurred 10 years ago as well as changes in frequency and severity are significantly influenced by characteristics of respondents, ethnic culture, geographical environment of farmer residences, farmland characteristics, and sources of livelihood. Ultimately, taking ethnic differences into consideration for long-term planning will be an important part of the local response to climate change in the future.