Abstract:The wind profile radar data observed from the western mountainous and eastern plain areas of Chengdu from 1 Jan to 31 Dec 2022 are used to analyse the regional differences in the vertical structure and daily variation trend of the boundary layer wind field. The results indicate that: (1) There are regional differences in the prevailing wind direction of the lower boundary layer in Chengdu, with north-north-east winds prevailing in the western mountains area and northeast winds prevailing in the eastern plains, and without seasonal difference. While there is no regional difference in the prevailing wind direction between the east and west regions in the middle and upper boundary layer, both occur alternately with northeast and southwest winds that are consistent with the direction of the western mountain range. (2) The variation trend of the average wind speed profile in the boundary layer between the eastern and western areas of Chengdu is consistent, and the horizontal wind speed in the eastern plain area of the same detection height layer is greater than that in the western mountains area. (3) The local mountain-valley breeze is significant in the lower boundary layer of the western mountains area; the valley breeze with southeast winds prevails during the day; and the mountain breeze with northwest winds prevails at night. (4) There are no regional differences in the diurnal variation characteristics of horizontal wind speed at the same detection height layer, and it is a “single peak and single valley” type, with a peak during the day and a valley at night. (5) The differences in the wind field characteristics of the lower boundary layer between the east and west regions of Chengdu are mainly caused by the local complex terrain of the western mountains area.