Abstract: The methods of linear regression, Mann-Kendal test, sliding T-test and correlation analysis were used to analyze the spatiotemporal variation of extreme temperature events in the Hedong region based on the daily temperature (maximum, minimum and average) data from 61 meteorological stations in the study area during the period of 1988-2017. The results showed that: ①In recent 30 years, the daily maximum and minimum temperature values, annual mean maximum and minimum temperature values, summer duration, tropical nights, warm days, warm nights, daily temperature range, warm-day duration and growing season were in an increase trend. Whereas the frost days, ice days, cold days, cold nights and cold-day duration were in a decrease trend; ② The change ranges of warming indices were obviously higher than those of cold ones. The warming ranges of diurnal indices were higher than those of nocturnal ones. The warming range was the highest in the Loess Plateau in east Gansu Province but the lowest in the Gannan Plateau; ③ Abrupt change of the most temperature indices occurred in the mid-1990s and early 21st century; ④ Most extreme temperature indices were closely related to the longitude and altitude. The variation of extreme temperature indices in the Hedong region was closely related to the regional warming.

Key words: extreme temperature')">

extreme temperature, cold(warm) index, index; spatiotemporal variation, Hedong region, Gansu Province