A strong cold air front is expected to sweep across Northern Vietnam from the evening of October 4, leading to a significant drop in temperatures. According to the National Center for Hydro-Meteorological Forecasting, the northern mountainous areas may see temperatures plummet to between 14 to 17 degrees Celsius, while the lowlands will experience a range of 19 to 22 degrees Celsius.

Starting from the evening of October 4, the northeastern region will begin to feel the effects of this cold front, which will gradually extend to other areas in Northern Vietnam and as far south as Thanh Hoa to Hue. Winds will shift to the northeast at levels 2-3 on land and 3-4 along the coast, with conditions expected to worsen in the Gulf of Tonkin.

In Hanoi, the cold air will reach the city early on October 5, bringing with it rain, moderate showers, and possible thunderstorms. The forecast indicates that from late evening on October 4 to the morning of October 5, the capital will experience rain, with localized heavy downpours expected.

As the cold front progresses, marine conditions will also deteriorate, with winds in the Gulf of Tonkin increasing to levels 6-7, gusting up to 8-9, and wave heights reaching between 2.0 to 4.0 meters. Fishermen and maritime activities are advised to exercise caution due to the expected rough seas.

The cold front is also likely to bring thunderstorms accompanied by strong winds, hail, and lightning, which could pose risks to agricultural production, infrastructure, and transportation. Localized heavy rainfall may lead to flash floods in small rivers and streams, landslides in steep areas, and flooding in low-lying regions.

As Northern Vietnam prepares for this cold spell, residents are advised to stay updated on weather conditions and take necessary precautions to ensure safety and minimize disruption to daily activities.