Ideas and knowledge about climate have changed considerably in history. Ancient philosophers like Hippocrates and Aristotle shaped the understandings of climate, which remained very influential until well into the eighteenth century. The Scientific Revolution of the seventeenth century gave rise to new ways of systematic instrument-based observation of and increased public interest in weather and climate. These developments led to a mechanistic understanding and a reductionist physical description of climate in the twentieth century, eventually in the form of a complex earth system. Furthermore, different understandings of climate co-existed in many periods of time. Only in the nineteenth and twentieth centuries specific scientific concepts of climate (a geographical understanding of climate in climatology until about the mid-twentieth century and a physical understanding of climate in climate science in the second half of the twentieth century) gained superior social credibility and cultural dominance. The understanding of climate involved more than the accumulation of scientific knowledge. It was rooted in social processes and cultural interests, which shaped different ideas of climate in different communities of actors and different historical times.