Surface Airways Hourly Observations - ASOS is digital data set DSI-3283 archived at the National Climatic Data Center (NCDC). This data set contains Automated Surface Observation System (ASOS) hourly surface weather observations that are measured primarily at major airports and military bases. The stations are operated by the US National Weather Service (NWS), the Federal Aviation Administration ... (FAA) and the Department of Defense (DOD). The NWS and FAA sites are located in the contiguous U.S., Alaska, Puerto Rico, Hawaii and other Pacific Islands. Observations are made by automated equipment and may be augmented by a human observer. The stations are usually fully instrumented and record a complete range of meteorological parameters. The major parameters are: Cloud height and amount, visibility, winds, precipitation, temperature, dew point temperature, relative humidity, pressure, and present weather.Users must be aware that DSI-3280 (C00215) and DSI-3283 are similar. The only difference is that DSI-3280 contains quality controlled data that has been hand checked by personnel at the National Climatic Data Center. DSI-3283 only contains data that is automatically quality controlled, therefore, it is considered to be "raw" data.