The northeast monsoon is forecast to arrive this weekend, and it will cause temperatures in Hanoi to drop to 10-13 degrees Celsius.
The National Hydro-Meteorological Forecasting Center said Sunday that the northern region has been overcast and foggy in the mornings due to the influence of weakened cold air and moisture brought by southeasterly winds from the sea.
Outdoor workers warm themselves with fire on a sidewalk of Hanoi, December 2021.
Starting Monday night the region will be affected by a weak cold air mass and the convergence of winds at altitudes of 3,000-5,000 meters, resulting in scattered rain and thunderstorms in some areas.
Two days later the rains will decrease and the weather will turn sunny again through the weekend.
From Dec. 17 the region is likely to see the strongest northeasterly winds so far this season, leading to the first severe cold spell of the winter.
The average daytime temperatures will drop to 15 degrees Celsius or lower in the lowlands and midlands and 13 degrees or lower in upland areas.
U.S. site AccuWeather forecast for Hanoi this week is for temperatures to range from 20 to 30 degrees, with some days experiencing rain and uncomfortable humidity.
By the end of the weekend, as the northeast monsoon arrives, temperatures would drop to 10-13 degrees, it said, adding that areas at altitudes of more than 1,500 m, such as Sa Pa City, would have temperatures of 14-20 degrees this week but as low as 2-9 degrees by weekend.
The central region will generally have dry weather except for Tuesday night and early Wednesday morning when rain will return due to the influence of a weak cold air mass.
Subsequently the weather will become sunny again.
From Dec. 17 this region too is expected to experience thunderstorms as the monsoon intensifies.
The southern and Central Highlands regions have entered their dry season, and will experience sunny weather this week.
Temperatures will range from 33 to 35 degrees in the south and 29 to 31 degrees in the Central Highlands.