“The previous version of the Autodesk Green Building Studio service supported weather locations mainly based on large airport sites. The 1.6 million virtual weather locations now supported by the service are located no more than 8.8 miles (14 km) from any given project location covered by the new data set. The new virtual weather locations were developed using weather data from a variety of government and other public sources, such as airports, ocean or river buoys, and aircraft and satellite readings. An observations-based physics model (mesoscale meteorological model) was then generated for each region. Access to the 1.6 million virtual weather location data set is available now to subscribers of Autodesk Ecotect Analysis 2010 during the term of their Subscription.”

Via Autodesk Press Release ..