Meteorological reanalysis models provide hourly snapshots of the state of the atmosphere over an extended period of time, typically since the dawn of the satellite era (1970s). In contrast to the operational weather forecast models on which they are based, reanalysis models focus on historical weather. From these historical snapshots a continuous weather time series can be assembled for all locations on Earth. For the purposes of ASHRAE, these “virtual” weather stations can then be used in the absence of more conventional stations, e.g. in the so-called “data deserts” found worldwide, to calculate design climatic conditions or as input to building simulation software. However, these virtual stations, being model-based, may not reflect the reality on the ground, putting building design at risk. ASHRAE has thus sponsored a research project (1745-RP) to evaluate the feasibility of the use of reanalyses by its members. This final report provides a summary the project and its findings.