Since Tuesday some places in the north have been experiencing high temperatures due to the impact of a low-pressure area in the west.
Temperatures recorded at 1 p.m. went up to 37 degrees in Son La and 34 degrees in Hanoi.
The National Center for Hydro-Meteorological Forecasting said the heat would cease once the cold front arrives. Besides, the clash between the masses of cold and hot air could create extreme weather phenomena like thunder, hail and strong winds.
U.S. weather forecast service AccuWeather said temperatures in Hanoi would be 20-27 degrees on Thursday before falling to 19-21 degrees and remaining that way until the end of the week.
Upland locations like Sa Pa in Lao Cai will have temperatures of 14-18 degrees.
From Friday the cold front will begin to affect the north-central region, ending a period of hot weather, taking temperatures down to 20-22 degrees.