Regional characteristics of hot days and tropical nights in the Honam area, South Korea

This study analyses the regional characteristics of heat extremes (hot days and tropical nights) in the Honam area of South Korea during the recent 23 years (1997–2019) by using weather station data. The results based on the binary classifications of stations, that is, inland versus coastal and urban versus rural, show hot days in inland regions are climatologically more frequent, and present higher interannual variability and more evident increasing trend than coastal regions. On the other hand, inland regions are exposed to less active tropical nights. The thermal characteristics associated with the oceanic (or continental) climate at which the station is located are responsible for the inland–coastal dependency of frequencies in hot days and tropical nights. The noticeable discrimination between urban and rural stations, categorized by population, appears only in tropical night occurrences, while hot days are independent of urban–rural contrast. In urban stations, tropical night occurrences are climatologically higher, interannually more active, and recently more frequent. Regarding the urban heat island, the additional nocturnal heat leads to the urban concentrated activity of tropical nights. Our analyses suggest that for accurate forecasts of hot days and tropical nights, different regional environments must be considered.