What raw data are available for global temperature monitoring?
The number of land surface weather stations in the Global Historical Climatology Network (GHCN) drops off in recent years. This fact is an indication of our success in adding historical data. Every month data from over 1,200 stations from around the world are added to GHCN as a result of monthly reports transmitted over the Global Telecommunication System. This number is up from what it was a decade ago due to systematic efforts by the Global Climate Observing System (GCOS) and others to encourage countries to send in CLIMAT reports. If NCDC relied solely on such data that would be the maximum number of stations available. But we have systematically sought to increase the data holdings in the past through international projects such as the once a decade creation of World Weather Records as well as NCDC’s own digitization of select Colonial Era archive data. The creation of the GCOS Surface Network is one example of a specific attempt to both enhance data exchange around the world and t
