When Is Vietnam's Typhoon Season? A Month-by-Month, Region-by-Region Guide

The same question comes up along Vietnam's coast every summer: when does typhoon season really start, and when is it safe to relax? Storms do not arrive at random. They follow a stable rhythm set by the tropical convergence zone, sea surface temperature and the monsoon winds. Know that rhythm and you know which months demand attention, which regions carry the most risk, and when to prepare.

When is the East Sea typhoon season?

The typhoon season over the East Sea generally runs from June through November, peaking in September, October and November. By then the ocean has stored months of heat, low-level moisture is abundant and upper-level winds are weak enough for a young circulation to hold together — the ingredients that let a shallow low become a tropical depression and then a typhoon.

That window is a statistical convention, not a hard rule. Systems occasionally form in April or May, and depressions can appear in December. Exceptions, yes, but the point stands: the season has soft edges and no official closing date.

How many storms in an average year?

Averaged over many years, the East Sea sees roughly 10 to 13 tropical storms and depressions per season. Only some make landfall on the Vietnamese coast; the rest curve toward the Philippines or southern China, or dissipate offshore.

Three caveats matter:

• It is a long-term average. Individual seasons swing widely around it.
• Storm count is not the same as damage. A quiet season with one landfall over a densely populated area at high tide can do more harm than a busy season that stays offshore.
• A tropical depression carries weaker winds than a typhoon but can still produce enormous rainfall when it meets terrain and a cold air outbreak. No "typhoon" in the bulletin does not mean no danger.

The seasonal drift: north early, south late

The most distinctive feature of Vietnam's storm season is that it migrates from north to south as the months pass, almost like a scheduled journey down the coast:

• June to August, early season. Storms mostly affect the north and north-central provinces. The convergence zone sits at a higher latitude, and systems forming in the northern East Sea tend to track northwest toward the Gulf of Tonkin.
• September to October, mid and late season. The focus shifts to the central coast, that narrow strip where mountains sit close to the sea — the harshest stretch of the calendar.
• November onward, late season. Activity slides further south into the south-central provinces and occasionally the far south, though landfalls there are much less frequent.

The pattern is a tendency, not a law; every season produces a system that ignores the calendar. Still, it explains why northern coastal families tie down roofs in midsummer while attention moves to the central provinces late in the year.

Why October and November bring the worst flooding to the centre

Central Vietnam does not only face wind. What makes the late season punishing is that several factors line up at once:

• A landfalling storm or depression pushes a deep layer of tropical moisture inland.
• Cold air pushes down from the north, meets that warm moist air and forces it upward, turning a few hours of rain into several days of it.
• The Truong Son range blocks the flow. Moist easterly winds are lifted by the terrain and dump extreme rainfall on the eastern slopes.
• Rivers are short and steep. Water reaches the lowlands within hours, so floods rise fast and drain slowly when high tides back up the river mouths.

The rain that follows a storm is therefore often more dangerous here than the storm itself. Damaging wind may last hours; flooding and landslides can last a week. Residents of Hue and neighbouring provinces know the cycle well, though familiarity itself breeds complacency when rain events arrive back to back.

Early-season and late-season storms are not the same

• Early-season systems usually form within the East Sea itself. The short travel distance means less warning time, though average intensity tends to be lower.
• Late-season systems more often arrive from the waters east of the Philippines, having had days to gather energy. They reach higher intensities and frequently combine with cold air to produce widespread rain.
• By late season, hillsides are already saturated from earlier rainfall, so even a moderate event can trigger a landslide.

Preparing on the season's schedule

• April and May, before the season. Trim trees near the house, check metal roofing, gutters and drainage — the cheapest work to do while everything is dry.
• June to August. Northern provinces enter their alert window. Keep torches, power banks and waterproof copies of documents ready.
• September to November. Peak period for the central coast. Store water and dry food for three to five days, raise electrical equipment off the floor, and decide in advance where you would evacuate to if you live low-lying or below a slope.
• In the 72 hours before landfall. Check updates every six to twelve hours, since both track and intensity can shift. Fill the fuel tank and charge every device.
• After the storm. Watch for fast-moving floodwater, downed power lines and follow-up rainfall. Much of the damage happens after the wind has stopped.

Reading forecasts well

Every storm bulletin has two halves: the track and the impacts. A track can shift by tens or hundreds of kilometres, so look at the whole affected zone rather than a single landfall point. The impacts — wind, rain, flooding and waves — determine what you should actually do today.

During the three peak months, the best habit is a quick check morning and evening, cross-checked against local warnings. You can look up conditions by province for the area you care about, and check tomorrow's forecast before locking in travel plans, a fishing trip or a harvest date during storm season.