Forecasters said hot weather is likely to continue for several more days in the region stretching from Thanh Hoa to Danang, as well as eastern areas from Quang Ngai to Dak Lak.
On June 17 and 18, temperatures in these areas are expected to reach 35-37 degrees Celsius, with some locations exceeding 38 degrees Celsius. Relative humidity is forecast to fall to 50-55 per cent during the hottest part of the day.
The weather agency noted that actual temperatures outdoors could be 2-4 degrees Celsius higher than forecast values, particularly in urban areas and on heat-absorbing surfaces such as concrete and asphalt.
Authorities warned that prolonged hot and dry conditions could increase the risk of fires in residential areas and forests, while also posing health risks such as dehydration and heat-related illnesses.
Health experts advised people to avoid prolonged exposure to direct sunlight between 10 am and 4 pm, stay hydrated and limit strenuous outdoor activities during periods of extreme heat.
On June 16, temperatures exceeded 37 degrees Celsius in several locations, including Dong Ha in Quang Tri Province, Danang and Tam Ky, with Tuy Hoa recording 38.2 degrees Celsius.