The NSF weather station is located on the roof of a 12 story building in downtown Arlington, Virginia. The data is accurate for that location but the location is not ideal for meteorological data gathering. Wind speeds at this elevation may be higher than at ground level and there may be some wind shading due to other tall buildings in the vicinity. On days with no wind, the temperature may be artificially high due to heating of the roof. This data is provided for non-scientific use as a public service. NSF and NCAR hold no responsibility for the accuracy of the data.