From January 19–25, Hanoi and northern provinces will see rain and a marked drop in temperatures starting January 21, reported the National Centre for Hydro-Meteorological Forecasting, adding temperatures are anticipated to drop as low as 10°C in Hanoi and near 0°C in the mountainous areas.

In early January 2026, residents in northern and north-central Vietnam are experiencing an extreme weather pattern: hot, dry days with strong sun and sudden plummeting temperatures at night, creating bone-chilling cold. Meteorologists attribute this to a modified cold air mass combined with a dominant continental high, which has dried out the lower atmosphere by cutting off moisture from the sea.

During daytime, direct sunlight intensifies heat and UV exposure, while relative humidity drops to 35–40%, causing dry skin, chapped mucous membranes, and heightened forest fire risks in mountainous areas. At night, with clear skies and no cloud cover to trap heat, temperatures drop sharply in a phenomenon known as surface heat radiation.

Nighttime lows in the plains are expected at 10–12°C, while midland and mountainous areas may see temperatures fall to 6–9°C. High-altitude peaks above 1,500 meters, including Fansipan, Phia Oac, and Mau Son, could reach 0°C or below.

Authorities warn of a high risk of frost and rime, which can damage crops and ornamental plants ahead of Lunar New Year celebration.

This “hot day, freezing night” pattern is expected to persist for 3–5 more days, before a strong cold air mass moves in.

Cold weather persists across northern Vietnam

VOV.VN - Cold weather continues across much of northern Vietnam on January 12, keeping overnight and early-morning temperatures low, while daytime conditions remain largely sunny.