While investments in climate information services (CIS) are on the rise, little objective evidence exists concerning efficacy and learning for future investments. To address these gaps, the Climate Information Services Research Initiative (CISRI) will: • Improve understanding of, and access to, knowledge on the effectiveness of CIS programming. • Produce evidence and tools to improve understanding of the factors and structures that influence CIS delivery, uptake, use and effectiveness. • Produce innovative evaluation methodologies and evidence on the degree of effectiveness of CIS. • Research, design and implement a plan for the dissemination, uptake and application of research, synthesis, evidence, and knowledge gaps.