Mai Van Khiem, its director, said the heat wave in the north would start subsiding on Saturday with a humid southeast wind from the sea bringing clouds.
Besides, a tropical depression is forming in the northern and central parts of the East Sea, which could bring rain in the next few days.
The heat wave would end in the central region soon after Sunday.
There are no signs of a heat wave returning to the two regions at least until early July, he said.
Under the influence of a western low-pressure area, the northern region has experienced a heat wave since June 11.
Temperatures of above 35 degrees Celsius were recorded in 23 out of 25 provinces and cities on Thursday.
In Hanoi the heat peaked in the last two days, with the maximum temperature exceeding 39 degrees on Thursday.
These temperatures were measured at meteorological offices, with actual outdoor temperatures being two to four degrees higher, and up to 10 degrees on concrete roads and buildings with metal roofs.
Central Vietnam has experienced a heat wave since June 9 with temperatures of 39-40 degrees in Do Luong District of Nghe An Province and Huong Khe District in Ha Tinh Province.