Coffee is one of the major crops produced in Colombia which is the third largest producer of coffee after Brazil and Vietnam. Together, these three countries produce more than 50% of the world's total coffee. One of the main challenges facing coffee producers in Colombia is to determine the effects of climate variability and climate change on their production. This paper presents CoffeeWKG, an RDF knowledge graph focused on weather conditions in the coffee-growing regions of Colombia over 15 years (2006-2020), to facilitate the understanding of climate impacts on coffee crops. CoffeeWKG enables the integration of heterogeneous sensor data collected from different weather stations and the definition of semantic metadata on agro-climatic parameters. This knowledge graph enables coffee growers and experts to explore and query historical weather conditions to establish a correlation between weather data and information on coffee crops, thus revealing the complex interaction between climate and production dynamics. This research is essential to improving the resilience of agriculture and optimizing resources in the face of changing climatic challenges.