Characteristics of Cluster High-Temperature Processes in the Beijing-Tianjin-Hebei Region Since 1980

XU Qihui; SHAO Lifang; GAO Xuxu; LI Xiaofan

doi:10.16032/j.issn.1004-4965.2025.022

Abstract：Based on the daily maximum temperature data from 174 meteorological stations in the Beijing-Tianjin-Hebei region from 1980 to 2023,the present study analyzed the spatial and temporal variations of high-temperature processes.The term cluster high-temperature process(CHTP)was also introduced to further understand these extreme weather events.The results revealed that the average number of high-temperature days per year in the region stood at 10.8,exhibiting a notable upward trend with a climate tendency rate of 1.9 days per decade.Temporally,the pattern of high-temperature days followed a decade-long cycle of"decrease-increase-decrease-increase",while spatially,the southern regions experienced more frequent and intense heatwaves compared to the northern ones.During the period from 1980 to 2023,a total of 149 CHTPs were recorded in the Beijing-Tianjin-Hebei region,predominantly occurring between May and August.The frequency of these events peaked in mid-June,exhibiting a unimodal distribution.Notably,the average duration,maximum extent of impact,and overall intensity of CHTPs have shown a significant increase over the years,with a particularly sharp rise in frequency and average intensity since 2010.In the past 44 years,seven of the ten strongest CHTPs appeared in the 21st century,and four occurred after 2009;the extreme daily maximum temperature mostly appeared in Shijiazhuang.Spatially,the majority of CHTP occurrences were centered in the central and southern parts of Hebei Province,with Shijiazhuang's southeastern region and Xingtai's northern area identified as high-incidence centers.Over the decades,these high-incidence areas have gradually expanded northward and eastward.Central and southern Beijing,southern Chengde,Tianjin,most of Tangshan,and western Qinhuangdao have witnessed an exponential rise in CHTP frequency,exhibiting a more pronounced increase compared to other regions.