To support global humanitarian organizations in carrying out interventions in project sites, information is needed that is situationally relevant and timely, while also being relevant to the HQs. The macro-level formal institutional conditions of the HQ and informal constraints at the project sites shape the design and content of Humanitarian Health Management Information Systems (HHMIS), and we focus in the paper on the aspect of information use. We use an ensemble view of the HHMIS, comprising of paper, the computerized system based on DHIS2, and other tools like Excel, to understand how these different components have varying affordances and are influenced differently by the formal and informal institutional conditions. Our theoretical perspective is thus shaped by the notion of “institutional affordances” which we draw upon to understand the affordance actualization of the HHMIS. We identify through our empirical analysis based on a project site in South Sudan, three key affordances relevant to the use of data – operationability, accountability and contextuability. Our analysis makes two key contributions: One, the different affordances of the components in the ensemble have interaction effects, sometimes positively influencing actualization and at other times is limiting. Two, we identify 4 sets of institutional (both formal and informal) influences on actualization coming from availability of information, existing maturity in the use of information, unique features of the humanitarian setting and technical features. We believe this paper makes an overall contribution in helping to situate the informational challenges faced by humanitarian organizations more firmly in the ICT4D agenda.