This document discusses hydroinformatics and its role in addressing climate variability. It begins by noting the increasing variability in climate and need for water management strategies that account for climate uncertainties. Hydroinformatics is then defined as the application of modeling, information and communication technologies, and computer sciences to problems of the aquatic environment. The key roles of hydroinformatics include developing better observation systems, predictive models, analytical methods to handle uncertainty, and changes to design and management practices in light of climate change. Hydroinformatics aims to integrate data, models, and people to support proper water resource management decisions.