 The GHCN is one of the primary reference compilations of temperature data used for climatology, and is the foundation of the GISTEMP Temperature Record.This map shows the 7,280 fixed temperature stations in the GHCN catalog color-coded by the length of the available record.Sites that are actively updated in the database (2,277) are marked as "active" and shown in large symbols, other sites are marked as "historical" and shown in small symbols.