The architecture of cloud computing is becoming ever more closely intertwined with geopolitics – from the sharing of intelligence data, to border controls, immigration decisions, and drone strikes. Developing an analogy with the cloud chamber of early twentieth century particle physics, this paper explores the geography of the cloud in cloud computing. It addresses the geographical character of cloud computing across two distinct paradigms. The first, ‘Cloud I’ or a geography of cloud forms, is concerned with the identification and spatial location of data centres where the cloud is thought to materialize. Here the cloud is understood within a particular history of observation, one where the apparently abstract and obscure world can be brought into vision and rendered intelligible. In the second variant, ‘Cloud II’ or the geography of a cloud analytic, the cloud is a bundle of experimental algorithmic techniques acting upon the threshold of perception itself. Like the cloud chamber of the twentieth century, contemporary cloud computing is concerned with rendering perceptible and actionable that which would otherwise be beyond the threshold of human observation. The paper proposes three elements of correlative cloud reasoning, suggesting their significance for our geopolitical present: condensing traces; discovering patterns; and archiving the future.