An Overview of the Global Historical Climatology Network Temperature Database

TLDR

The Global Historical Climatology Network version 2 temperature database was released in May 1997. This paper details the enhancements made to the database. The dataset comprises monthly surface observations from roughly 7,000 worldwide stations and incorporates additional stations, maximum–minimum temperature records, rigorous data‑quality assessments, objective homogeneity adjustments, rich metadata, and a framework for regular updates. These improvements establish a new benchmark for global climate databases.

Abstract

The Global Historical Climatology Network version 2 temperature database was released in May 1997. This century-scale dataset consists of monthly surface observations from ~7000 stations from around the world. This archive breaks considerable new ground in the field of global climate databases. The enhancements include 1) data for additional stations to improve regional-scale analyses, particularly in previously data-sparse areas; 2) the addition of maximum–minimum temperature data to provide climate information not available in mean temperature data alone; 3) detailed assessments of data quality to increase the confidence in research results; 4) rigorous and objective homogeneity adjustments to decrease the effect of nonclimatic factors on the time series; 5) detailed metadata (e.g., population, vegetation, topography) that allow more detailed analyses to be conducted; and 6) an infrastructure for updating the archive at regular intervals so that current climatic conditions can constantly be put into historical perspective. This paper describes these enhancements in detail.