On August 15, temperatures of 35-37 degrees Celsius are forecast from Quang Tri to Danang and in eastern areas from Quang Ngai to Dak Lak, as well as Khanh Hoa, with some places exceeding 37 degrees. Minimum humidity is expected at 55-60 per cent, with the hottest period from 11 am to 5 pm.
Similar conditions are forecast on August 16 from Nghe An to Danang, eastern areas from Quang Ngai to Dak Lak, and Khanh Hoa. Minimum relative humidity is expected at 55-60 per cent.
Forecasters warned that actual outdoor temperatures could be 2-4 degrees higher than forecasts, or even more over surfaces such as concrete and asphalt.
The heatwave has been assigned a level-one disaster risk warning.
Hot and dry conditions, combined with increased electricity use, could raise the risk of fires in residential areas, while prolonged exposure to high temperatures could cause dehydration.
Health experts advised people to avoid outdoor activities between 10 a.m. and 4 pm where possible and to use protective clothing, hats and sunglasses when outside.
People working in hot conditions are advised to drink at least 1.5-2 litres of water a day and avoid prolonged or strenuous physical activity.
On August 14, temperatures at 1 pm were generally 35-36 degrees Celsius from Thanh Hoa to Danang, eastern areas from Quang Ngai to Dak Lak, and Khanh Hoa.
Several locations recorded higher temperatures, including Thanh Hoa and Hoai Nhon at 36.8 degrees Celsius, Vinh and Quang Ngai at 36.4 degrees and Tam Ky at 36.8 degrees.
Average temperatures nationwide in August are forecast to be 0.5-1 degree Celsius above long-term averages, with some areas even warmer.
The south-central coast is expected to see more hot days than usual this month, including severe heat, while northern Vietnam and areas from Thanh Hoa to Hue are forecast to see fewer.