This paper outlines a methodological strategy for incorporating weather and long-term climate conditions into impact assessments, based on an IFAD-supported project that invested in grain storage in Chad. First, the paper explores a range of weather and climate variables from different sources to determine the best indicators of weather conditions and corresponding historical climate conditions. Next, the inclusion of climatic variables to match treatment and control households, and their impact on outcomes, is evaluated. During the crop season surveyed, rainfall and temperature patterns were favourable with few significant weather shocks. However, households in areas with lower rainfall and greater incidence of high temperatures had lower grain yields and dietary diversity.