A worker at a construction site in Hà Nội in the hot weather. — VNA/VNS Photo Thành Đạt

HÀ NỘI — Northern and north-central provinces are sweltering under a severe hot wave, with temperatures in some places topping 40 degrees Celsius, announced the National Centre for Hydro-Meteorological Forecasting.

The extreme weather, which will cause temperatures to stay above 35 degrees Celsius from 10 to 19 hours per day, will also cause low humidity of between 40 and 60 per cent.

Hà Nội will experience extremely hot days, with the lowest temperatures around 29 – 31 degrees and the highs reaching 39 – 40 degrees. There will be places where the temperatures will exceed 40 degrees.

The heatwave is forecast to last through June 21.

Demand for electricity is likely to increase during the day. Vietnam Electricity (EVN) has advised agencies, production establishments and households to use electricity safely, economically and effectively.

Nguyễn Tiến Toàn from the Weather Forecast Office of the National Hydrometeorological Forecast Centre told Lao động (Labour) newspaper that the heatwave was caused by a low-pressure system in the west combined with the foehn effect. 

The foehn effect makes the heat last longer during the day and lowers humidity, posing a high risk of fires, he said.

The hot weather has negatively affected the daily activities of people and threatened residents' health.

Nguyễn Văn Nam, a shipper in Hà Nội, said he had to refuse many orders due to the hot weather. "It is too hot, particularly between 11am and 2pm. Many shippers like me have to stop working during that time to avoid the heat. It will be very tiring and you easily get dehydrated," he said.

Medical experts warn of dehydration, exhaustion, and heat stroke as the human body is exposed to high temperatures for a long time.

The National Centre for Hydro-Meteorological Forecasting also warned that Hà Nội and other provinces in the north will see a high ultraviolet (UV) index.

The maximum UV index usually occurs from 10am to 1pm.

A UV index of 2.5-5.4 is moderate, 5.5-7.4 is high risk, 7.5 -10.4 is very high, and more than 10.5 or higher is considered dangerous.

From June 17 to 19, the UV index in Hà Nội and other localities was forecast to reach 9-10.

The country is projected to face more widespread heatwaves this month. — VNS