The summaries of daily land surface observations in this data set
are primarily from stations in the National Weather Service (NWS)
cooperative station network, but also include NWS principal (first
order) climatological stations, and stations supported by the
Federal Aviation Administration (FAA), National Park Service (NPS),
Bureau of Land Management (BLM), U.S. Forest Service (USFC), U.S.
Geological Survey (USGS), and Tennessee Valley Authority (TVA),
along with a handful of stations at Air Force and Navy bases. The
sites are located in the contiguous U.S., Alaska, Puerto Rico,
Virgin Islands, Hawaii and other Pacific Islands.
The major parameters are daily weather, precipitation, snowfall,
snow depth, maximum temperature, minimum temperature, and
observation temperature. The earliest data is for 1854, but most
stations begin in 1948. Periods of record vary widely among the