Cold Air Arrives on the Second Day of Tet, Bringing Chilly Weather to Northern Vietnam

Cold air spreads across the North during Tet

On February 18 (the second day of the Lunar New Year holiday), a cold air mass affected the Northeast, most of the North Central region, and some areas of the Northwest. The shift in air mass brought a noticeable change in conditions: light rain occurred in a few places and temperatures generally fell by around 2–4°C compared with prior conditions.

The arrival of this cold air was not limited to one small area. The system influenced a broad stretch of northern and north-central Vietnam, and forecasters indicated it would continue to expand its reach through the day and night of February 18, then extend further afterward.

How the cold air was expected to evolve

During the day and night of February 18 (still within the second day of Tet), the cold air was expected to continue affecting other parts of the North Central region and the Northwest. After that, it was forecast to influence the Central Central region as well.

This type of progression matters for people planning holiday travel or outdoor activities during Tet, because it suggests that the cooling trend and unsettled conditions would not remain confined to the far north. Instead, the cooler air was projected to move southward step by step, bringing changes in temperature, wind, and rainfall patterns along the way.

Winds on land: Northeast flow strengthens

On land, northeast winds were reported at level 2–3, with stronger winds of level 3–4 in coastal areas. While these wind levels are not extreme on their own, they can contribute to a colder “feel,” especially when combined with damp conditions such as drizzle or light rain.

For daily life during the holiday period, this means that even where rainfall is limited, the combination of cooler air and steady wind can make outdoor visits, temple trips, and travel between destinations less comfortable than under calm, dry conditions.

Rain outlook: scattered light rain in the North Central region

From February 18 to February 19, the North Central region was expected to see rain and scattered light rain. The forecast emphasized that precipitation would be present across the period, though not necessarily heavy everywhere.

Light rain during cooler weather can still have practical impacts. Roads and sidewalks may become slick, visibility can be reduced at times, and outdoor gatherings may need adjustments. For travelers moving between provinces, it can be useful to anticipate intermittent drizzle rather than continuous downpours, based on the outlook provided.

Temperature drop and cold conditions in the North and Thanh Hoa

Across the Northern region and Thanh Hoa, conditions from February 18 to February 19 (the second to the third day of Tet) were forecast to turn cold. In mountainous areas, some locations were expected to experience more intense cold.

During this cold air episode, the lowest temperatures in the Northern region and Thanh Hoa were generally expected to range from 16–19°C. In mountainous areas, some places were forecast to fall below 13°C.

This difference between lowland and mountainous zones is important for anyone planning to travel to higher elevations during the holiday. A temperature below 13°C can feel significantly colder, particularly with wind and moisture in the air. People visiting mountain districts may need to plan for warmer clothing and take additional care if traveling early in the morning or later at night, when temperatures tend to be at their lowest.

Hanoi: cooler days with light rain in places

In Hanoi, the outlook noted light rain in a few areas, along with cold conditions from February 18 to February 19. The lowest temperatures during this cold air event in the capital were commonly expected to be in the 17–19°C range.

For residents and visitors, this suggests a Tet period in Hanoi characterized by cool air rather than severe cold, but still chilly enough to change plans for outdoor activities. Light rain in some locations may also add to the sense of damp cold, which can be more uncomfortable than the temperature alone might suggest.

Marine conditions: strong winds and rough seas

Alongside the changes on land, the cold air surge was associated with stronger northeast winds and increased wave heights at sea.

In the Gulf of Tonkin, northeast winds were reported at level 5, sometimes reaching level 6, with gusts at level 7–8. Sea conditions were described as rough, with waves around 1.0–2.5 meters.

In the northern area of the East Sea (including the Hoang Sa maritime area), northeast winds were reported at level 6. In the northeastern waters of this zone, winds could at times reach level 7, with gusts at level 8–9. Sea conditions were described as very rough, with waves around 3–5 meters.

Further south, in the waters from Khanh Hoa to Ca Mau, as well as the central part of the East Sea and the western waters of the southern East Sea (including the western part of the Truong Sa maritime area), northeast winds were expected to strengthen to level 6, with gusts at level 7–8. Sea conditions were described as rough, with waves around 2.5–3.5 meters.

Why the sea warning matters during the holiday period

Experts cautioned that strong winds, gusts, and large waves at sea could affect the operation of ships and other activities. This warning is particularly relevant during holiday periods, when travel demand can rise and some coastal communities may see increased movement of people and goods.

Rough sea conditions can influence the safety and scheduling of maritime travel, as well as routine fishing and transport operations. Even when conditions are not uniform across all waters, the forecast indicates multiple zones experiencing strengthened winds and significant wave heights, underscoring the need for careful planning and attention to marine weather updates.

Key figures at a glance

• Date of impact: February 18 (second day of Tet) with continued influence into February 19
• Areas affected early: Northeast, most of the North Central region, and some parts of the Northwest
• Temperature change: generally down about 2–4°C in affected areas
• Lowest temperatures (North and Thanh Hoa): commonly 16–19°C; mountainous areas in some places below 13°C
• Hanoi lows: commonly 17–19°C
• Rain: scattered light rain in the North Central region from February 18 to 19; light rain in a few places in Hanoi
• Gulf of Tonkin: NE wind level 5–6, gusts 7–8; waves 1.0–2.5 m
• Northern East Sea (including Hoang Sa area): NE wind level 6; in the northeast at times level 7, gusts 8–9; waves 3–5 m
• Waters from Khanh Hoa to Ca Mau and parts of the East Sea (including western Truong Sa area): NE wind strengthening to level 6, gusts 7–8; waves 2.5–3.5 m

What this forecast means for travelers and residents

The forecast points to a Tet holiday period shaped by a clear shift toward cooler weather in the North and North Central regions, along with light rain in some areas. For many people, the most immediate change would be the drop in temperature and the return of a winter-like feel, particularly in the evenings and early mornings.

In practical terms, residents in northern provinces and Thanh Hoa may experience a couple of days of cold conditions, with the possibility of stronger cold in mountainous areas. In Hanoi, the combination of cool air and occasional light rain may influence outdoor plans, even if temperatures remain in the upper teens.

At sea, the stronger northeast winds and higher waves across multiple maritime zones are a significant part of the overall weather picture. The expert warning about potential impacts on vessels and other marine activities highlights that the cold air event is not only a land-based concern but also a maritime safety issue.

Context: cold air had already affected parts of the Northeast earlier

Before February 18, cold air had already influenced some places in the northeastern part of the Northern region on February 17 (the first day of Tet). This provides context for the broader expansion reported on February 18, when the cold air mass was described as affecting a wider set of areas, including most of the North Central region and parts of the Northwest.

Overall, the described pattern is one of a cold air mass first reaching parts of the Northeast, then spreading across northern and north-central areas, with continued influence expected into subsequent regions. The forecast details on wind, rain, and sea conditions help outline how that shift could be felt across daily life, travel, and maritime operations during the holiday period.