The initial result shows that in general, in the north of the study area, the large number of hot days occurred in the plain, and tended to decrease westward and eastward. In the south, this number tends to increase from the west to the east. Especially, the largest number occurred in two areas: The Ma and Ca River's valleys (Thanh Hoa and Nghe An provinces) and the coastal areas (Thua Thien Hue province), creating two heat centers in Tuong Duong district, Nghe An province and Nam Dong district, Thua Thien Hue province.
