Genealogies of life assurance have tended to focus on the governmental possibilities of actuarial calculations of mortality, but the case of foreign residence assurance draws attention to other ways in which British companies calculated climate risk between 1840 and 1940. Drawing on archival research, this paper demonstrates that the extra charges imposed on life assurance policies for foreign residence invited conversations about the risks of climate and mortality in countries beyond Britain, drawing on both contemporary climate science and other arguments about climate pathology. Climate risks, however, had to be made to work for both life assurers and policyholders through far-reaching social-material networks, and firms frequently tinkered with arrangements of people, ideas, and artefacts in ways that enabled a mapping and governing of such risks. Whether ideas of climate circulating in life assurance were believed or not, they had effects and policyholders submitted to them. Drawing on archival material from several British life assurance companies, including some detailed cases of assured migrant lives, the paper explores how companies made risk calculations in ways that had consequences for ordinary decisions and practices. In so doing, the paper contributes to debates about life assurance and governmentality, showing that foreign residence policies enabled businesses to secure their risks in an era of imperial expansion. But this is no simple story of power and imperialism. Businesses constantly tinkered with their policies, drawing on climate science and medical understandings, but only as part of an always messy, changing assemblage.