Taiwan Typhoon Warnings Explained (Sea Warning, Land Warning, Typhoon Day)
The sea warning went up at half past eight in the evening. The land warning came the following afternoon, nineteen hours later. Between those two announcements the ferries stopped, the fishing fleet came in, and in Taipei absolutely nothing happened.
That gap is the thing worth understanding about Taiwan's system, and it is why visitors so often conclude the warnings are meaningless. They are not. They are two separate announcements about two separate places, and the first one is not about you unless you are on the water.
And the thing everybody actually wants to know, whether tomorrow is a day off, is not decided by the weather service at all.
Photographs here are stock images for illustration and are not pictures of the events described.
The Sea Warning comes first and most people ignore it
The Central Weather Administration issues a sea warning roughly twenty-four hours before a typhoon's gale-force wind radius is expected to reach waters within 100 kilometres of Taiwan, Kinmen or Matsu. Gale force here means Beaufort 7, about 30 knots, which is the same threshold most agencies in the region use to draw the outer ring of a storm.
Notice what is being measured. Not the eye, not the centre, not the point of closest approach. The outer edge of the storm's wind field, and its distance from the coast rather than from land. A typhoon can trigger a sea warning while its centre is still several hundred kilometres away and forecast to miss the island entirely.
That is why the sea warning feels like a non-event on shore. The sky is normal, the shops are open, and the warning is genuinely aimed at somebody else. It is a shipping and fishing alert, and it is doing its job even when nothing happens to you.
What it does do is start the machinery. Ferry operators begin cancelling, airlines start opening flexible rebooking windows, and the outlying islands lose their connections first. If your plans involve Penghu, Green Island, Orchid Island, Xiaoliuqiu, Matsu or Kinmen, the sea warning is your warning, not the land one.
The Land Warning is the one that changes your day
The land warning comes about eighteen hours before that same gale-force radius is expected to touch land. Six hours later than the sea warning, and roughly one working day before anything happens to you.
Both warnings are updated at least every three hours once issued, and the interval tightens as the storm closes in. The bulletin page moves to something closer to hourly when a system is near. If you are watching a storm, that update rhythm is a better signal of seriousness than the wording of any single bulletin.
The land warning is the trigger for the rest of the country. Highway agencies start planning closures, rail operators begin publishing reduced timetables, and the county and city governments start working out what to announce that evening.
It is worth being clear about what the land warning is not. It is not a statement that your town will be hit. Taiwan is 394 kilometres long with a mountain range down the middle, and a land warning covering the island can mean a battering in Hualien and drizzle in Taichung. The warning covers the storm's reach, not its damage.
A Typhoon Day is decided by your mayor, not by the CWA
This is the part that surprises people. The weather service does not close anything. It supplies forecasts and rain and wind guidance to local governments, and each city and county head then decides independently whether to suspend work and classes in their own jurisdiction.
The criteria they work from are specific. A suspension is justified when an area is forecast to fall inside the storm's wind radius within the next four hours with average winds of 14 metres per second or more, about 50 kilometres per hour, or gusts of 25 metres per second, about 89 kilometres per hour. It is also justified on rainfall alone, at 350 millimetres in lowland areas or 200 millimetres in the mountains, where a disaster has already happened or looks likely.
There is a third clause that covers everything else. If terrain or rainfall has cut transport, water or power in a way that makes getting to work or school unsafe, that is grounds on its own, regardless of the wind numbers.
Because the decision is local, the map goes patchy. Neighbouring cities coordinate within shared commuting zones so that somebody living in Taipei and working in New Taipei is not caught between two different answers, but you will still see one county closed and the next one open on the same morning.
Announcements covering the following morning generally land the night before, between seven and ten in the evening. That window is worth knowing, because it is the difference between finding out in time and finding out at the station. The consolidated official list is published at https://www.dgpa.gov.tw/typh/daily/nds.html
What actually stops, and in what order
Typhoon Bavi in July gave a clean sequence. Ferries went first, with 116 sailings cancelled across 13 routes, including the outlying island services and the cross-strait links. Then aviation, with more than 1,200 flights cancelled and every international departure and arrival at Songshan, Taoyuan and Kaohsiung scrapped for a full day.
The order matters more than the totals. Ferries stop early because a small vessel in a rising swell is dangerous long before an airport becomes unusable. Flights stop later but recover more slowly, because aircraft end up in the wrong cities and the backlog has to be flown out over the following days.
Ground transport is the odd one out. Metro systems generally keep running, rail services usually thin out rather than stop outright, and the thing that actually strands people is the highway network rather than the trains.
Shops and restaurants follow the suspension announcement rather than the weather. In a city that has been closed for the day you will find convenience stores open and very little else. That is the practical reason a day off in a typhoon is duller than it sounds.
The warning lifts before the roads reopen
The land warning is cancelled once the gale-force radius has moved off the island, and the sea warning is cancelled after that. Both can be lifted on a bright morning, and both routinely are.
The mountains do not follow that schedule. The Suhua Highway on the east coast and the Central Cross-Island Highway close for days after a serious storm while crews clear landslides, and the reopening is announced by the highway authorities rather than by the weather service. If your itinerary crosses the island or runs down the east coast, that is the number to chase, not the warning status.
This is the same gap that catches people everywhere in the region. The alert is a forecast product and it ends when the forecast condition ends. The disruption is a physical problem and it ends when somebody has moved the rock off the road.
For planning purposes the honest summary is short. A sea warning means check your ferry. A land warning means check the evening announcement. A day off means stay where you are and expect a quiet, slightly boring day indoors. And the morning after the all-clear, check the roads before you check the sky. Current bulletins in English are at https://www.cwa.gov.tw/V8/E/
What I find genuinely sensible about the Taiwanese setup is that it keeps the forecast and the decision in separate hands. The weather service says what the storm will do and stops there. Somebody elected in your city decides what that means for your Monday, and has to answer for it if the call goes wrong in either direction. It produces some inconsistent mornings, and it also means nobody sitting in Taipei is deciding whether Hualien goes to work.
The gap between the two warnings, and what fills it
Taiwan's Central Weather Administration issues a sea warning when storm-force winds are expected in the waters around the island, and a land warning when they are expected over land. The sea warning always comes first, and the interval between them is typically somewhere around half a day to a day depending on the storm's speed and angle of approach. A fast system closing from the east can compress it to a few hours; a slow one curving up from the south can stretch it well past a day.
What happens in that interval is more useful than either announcement on its own. The offshore island routes stop almost immediately: Penghu, Matsu, Green Island and Orchid Island are served by ferries and small aircraft that suspend on sea state, and they suspend on the sea warning rather than waiting for the land warning. If any part of your itinerary involves those islands, the sea warning is your warning, and treating it as a marine-only notice is how people end up stranded on Green Island for three days.
On the main island in that same window, almost nothing changes. Trains run, the metro runs, shops open, and the high-speed rail keeps its schedule. This is the source of the confusion: a visitor reads that Taiwan is under a typhoon warning, looks out of the window at ordinary weather, and concludes the whole system is theatre.
The land warning is the one that starts the machinery, and even then the closure decision is separate from it. Taiwan's day off is announced by each local government, city by city and county by county, usually in the evening for the following day. Taipei City and New Taipei City can and do decide differently from each other despite sharing a metro system. The announcement covers work and school together — it is one decision, not two — and when it is made, the city genuinely stops: offices close, most shops close, and the metro runs a reduced service.
For the traveller the practical rule is that the local government announcement, not the CWA warning, is the thing that determines whether tomorrow exists. It is published in Chinese first and carried in English shortly after, and it arrives late in the evening, which is inconvenient if you are trying to decide about a morning train.
One more piece of geography. Taiwan's central mountain range runs most of the length of the island and rises above 3,000 m, and it does two things to a typhoon: it wrings enormous rainfall out of the eastern slopes, and it disrupts the storm's structure as it crosses. That means the east coast — Hualien, Taitung, the Suhua highway — takes a completely different storm from Taipei, and road closures there outlast the warning by days. A west-coast itinerary and an east-coast itinerary are not the same trip in typhoon season.
When storms actually reach Taiwan, counted from the record
Taiwan's season is usually described as running from July to September. Counting actual approaches rather than repeating the range gives a sharper picture, and one month stands well clear of the others.
| Month | Storms within 300 km (2016–2025) |
|---|---|
| June | 2 ■■ |
| July | 10 ■■■■■■■■■■ |
| August | 6 ■■■■■■ |
| September | 6 ■■■■■■ |
| October | 2 ■■ |
| November | 1 ■ |
| All other months | 0 |
Twenty-seven storms in ten seasons. July is the peak, and by a wide margin — ten against six for each of August and September. That is worth stating plainly because Taiwan's neighbours peak later: Okinawa's worst month is August and Korea's are August and September. A traveller moving between them in a single trip is not facing one season but three, staggered.
The November entry is not noise either. It is a reminder that the tail of the season reaches further into autumn on Taiwan's side of the strait than most itineraries assume.
Counts computed for this page from the RSMC Tokyo best track archive published by the Japan Meteorological Agency. Method: every storm of tropical-storm grade or higher whose best-track position passed within 300 km of the reference point, counted once per storm, by the month of closest approach, for the ten complete seasons 2016–2025. Data downloaded 26 September 2026.
Warning systems by region
This page is part of a series that takes each warning system in the western Pacific on its own terms rather than translating them into one another.
- Korea and Jeju
- Okinawa
- Philippines: wind signals
- Philippines: rainfall warnings
- Hong Kong
- Okinawa: US base alerts
- All regions compared
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