Environmental sanitation workers cover themselves from head to toe while working in scorching weather conditions. VNA/VNS Photo Kim Anh

HÀ NỘI — Many localities across Việt Nam recorded temperatures approaching 39 degrees Celsius on Sunday, as meteorologists warned of prolonged extreme heat and increased risks of heat shock, dehydration and fires.

According to the National Centre for Hydro-Meteorological Forecasting, severe heatwaves affected areas from Thanh Hóa Province to Đà Nẵng City and eastern Quảng Ngãi Province, where temperatures at 1pm ranged from 37-38 degrees Celsius, with some locations exceeding 38 degrees Celsius.

Among the hottest areas were Vinh in Nghệ An Province at 38.6 degrees Celsius, Hà Tĩnh at 38.8 degrees Celsius, Ba Đồn in Quảng Trị Province at 38.4 degrees Celsius, and Quảng Ngãi at 38.4 degrees Celsius.

Northern localities and eastern areas stretching from Gia Lai Province to Lâm Đồng Province also experienced intense heat, with temperatures generally between 35-37 degrees Celsius and some places surpassing 38 degrees Celsius. Monitoring stations in Vĩnh Yên in Phú Thọ Province, Bắc Ninh Province and Láng in Hà Nội all recorded temperatures of 38.8 degrees Celsius, while Hoài Nhơn in Gia Lai Province reached 38.2 degrees Celsius. Relative humidity in many areas dropped to between 40 and 50 per cent.

Forecasts indicate that from May 25-26, central localities from Thanh Hóa Province to Đà Nẵng City and eastern Quảng Ngãi Province will continue to face severe and exceptionally severe heat, with temperatures forecast to range from 38-40 degrees Celsius and potentially exceed 40 degrees Celsius in some places. Humidity is expected to remain low at 40-45 per cent, with hot conditions lasting from 9am to 6pm.

Northern regions and eastern areas from Gia Lai Province to Lâm Đồng Province are also forecast to experience widespread heatwaves, with temperatures of 36-38 degrees Celsius and some areas likely to exceed 39 degrees Celsius.

Meanwhile, southeastern provinces are expected to record highs of 35-36 degrees Celsius, with some areas surpassing 36 degrees Celsius.

Nguyễn Văn Hưởng, head of the weather forecasting department at the national forecasting centre, warned that actual outdoor temperatures could feel 2-4 degrees Celsius higher than forecast levels due to heat retained by concrete and asphalt surfaces.

He said the heatwave in northern regions and the southeast could persist until around May 27, while central regions may continue experiencing extreme heat until about May 28. Authorities have issued a level-1 natural disaster risk warning for the heatwave.

Experts warned that prolonged hot and dry weather, combined with surging electricity demand, could increase the risk of fires and explosions in residential areas as well as forest fires. Prolonged exposure to high temperatures may also lead to dehydration, heat exhaustion and heat stroke.

Health experts advised people to avoid going outdoors between 10am and 4pm unless absolutely necessary. Residents are encouraged to wear protective clothing, hats, sunglasses, and masks when outside, and to avoid prolonged physical activity in hot conditions.

People working outdoors or in high-temperature environments were advised to drink 1.5-2 litres of water per day to prevent dehydration and electrolyte imbalances, which could lead to cardiovascular collapse or severe health complications.

Meteorologists said heatwaves are expected to intensify across much of the country throughout May, with northern and north-central provinces likely to record more hot days than the historical average.

Looking ahead, forecasters said temperatures in northern and southern regions are expected to ease from around May 27 as scattered showers and thunderstorms move in. Northern localities may experience rain from the evening of May 27 through May 30, while southern areas are forecast to see afternoon and evening thunderstorms, with some places likely to experience heavy rain.

Central provinces from Thanh Hóa Province to Đà Nẵng City and south-central coastal areas are also expected to receive scattered showers and thunderstorms from May 28-30.

Authorities warned that thunderstorms could bring whirlwinds, lightning, hail and strong gusts. VNS