Changes of extreme temperature events in Three Gorges area, China

Meteorological data and heat stress indices from 1958 to 2007 in the Three Gorges area were investigated in this study. It is found that there is a (1) mild augmentation of the diurnal temperature range in the region (2) antithetical trends in mean\maximum\minimum temperatures, indicated by warmer winters and slightly cooler summers and (3) declining linear trends of the number of (very) hot days and annual frequencies of (long) heat waves, despite rising frequencies of (very) hot days and annual short heat waves. A U-shape was detected for all the climatic indices, with low values occurring mostly in the 1980s. However, spatial variations exist. Decreasing trends of hot days and frequency of heat waves were more evident in areas like Shapingba, where high annual temperatures were recorded. The finding also suggests a positive impact of the subtropical high on high temperatures and extreme temperature events.