This study was conducted to understand how rice farmers living in the highlands of Lake Toba, both as irrigated and non-irrigated rice farmers, began not to follow the traditional knowledge (TK) that they had for generations due to climate change. They develop ways to adapt and use specific strategies to maintain rice as a source of income and their lives. Using a qualitative research approach with a total of 130 respondents. Convenience and purposive sampling were used to identify potential respondents, and thematic analysis was used for data analysis. Data was collected through interviews with rice farmers about every process of growing rice, from sowing seeds to harvesting by separating filled and empty rice seeds. The results revealed that both categories of rice farmers have their behavior in dealing with climate change but found similar views in adjusting traditional knowledge (TK), such as to cope with rice planting and crop failure, joining farmer groups, not relying on climate change information, changing crop varieties and pumping system. On the one hand, this study shows that rice farmers can still maintain their livelihoods with different infrastructure (irrigation and non-irrigation). On the other hand, climate change is interpreted with the fading of traditional knowledge (TK) and changes in new strategies to cope with it. This research implies that the government, through its populist policies, should be able to see the vulnerability of rice farmers to climate change. They can only survive for a subsistence life without being able to improve the economic welfare of the family. Future studies can be extended to the entire Lake Toba highland region, specifically supporting traditional knowledge in rice farming by collecting different perspectives, and quantitative approaches can be used to gather more perspectives of broad opinions.