Evaluating the Spatial and Temporal Characteristics of Summer Urban Overheating through Weather Types in the Attica Region, Greece

In this study, we investigated the association between weather type (WT) and urban heat island intensity (UHII) in the region of Attica (Greece). The application of the methodology resulted in ten WTs over the Attica region. The UHII was calculated for every hour of the day from 2008 to 2017, using a new air temperature dataset produced by Copernicus Climate Change Service. To obtain more definitive findings about the relationship between WTs and UHII, we also used the upper 5% of UHII (urban overheating, UO). UO was estimated for two time intervals (daytime and nighttime) and for the warm period (June-September). The UHII frequency distribution, as well as the spatiotemporal characteristics of the UO, were also investigated. It was found that UO was amplified under WT2 during the night, while WT10 was mainly related to increased UO magnitudes in the daytime in all months. Furthermore, analysis results revealed that the UO effect is more pronounced in Athens during the night, especially at the Athens center. The daytime hot spots identified were mainly in suburban and rural areas. Therefore, this methodology may help with heat mitigation strategies and climate adaptation measures in urban environments.