A New Evaluation of Observed Changes in Diurnal Temperature Range

Abstract

Due to spatial heterogeneity, the global diurnal temperature range (DTR) change trends vary across data sets. By updating the C-LSAT data set to version 2.1, this study systematically evaluates long-term DTR trends at global and continental scales since 1900. The results indicate that improvements in temporal and spatial data coverage, particularly after 2014, along with data homogenization, have significantly enhanced the reliability of global and regional DTR assessments. Since 1900, the global mean DTR has declined at a rate of −0.025°C per decade, with the most pronounced decreases observed from the 1950s to the 1980s, especially in Asia and Africa. However, in recent decades, DTR trends have reversed, with the global DTR increasing at a rate of 0.136°C per decade since 1998, particularly in Europe, North America, and the Southern Hemisphere. These findings confirm previous studies on DTR trends and their causes, providing updated, reliable estimates of global and regional changes.