Monsoon and Typhoon Season in Asia: What It Means for a Cruise
Asia itineraries get rewritten more often than any other region I sail, and almost none of it is random. Two different weather systems drive it.
One is the typhoon, which moves and gives you a few days of warning. The other is the monsoon, which is really just a calendar.
My quick take
The first time a captain told me we were dropping a Japanese port because of a storm several hundred miles away, I assumed he was being dramatic. He was not, and the swell that met us the next morning made his point for him.
What I would do is treat typhoon risk and monsoon risk as two separate booking decisions. A typhoon is a gamble you can price, while a monsoon is a fact you can look up before you pay anything.
The thing I would not do is book late August in Japan and then act surprised. August is the busiest month on the Japan Meteorological Agency’s own thirty year record, and the cruise lines know it perfectly well.
The quick facts
- No closed season: the western North Pacific makes typhoons in every month, unlike the Atlantic. The risk that reaches an itinerary runs July through October.
- Japan’s numbers: the Japan Meteorological Agency puts the 1991 to 2020 average at 25.1 typhoons forming a year, 11.7 approaching Japan and 3.0 making landfall. Formation peaks at 5.7 in August and 5.0 in September.
- Hong Kong counts in numbers: the scale runs 1, 3, 8, 9 and 10, with nothing in between. Signal 1 goes up when a cyclone is centered within about 500 miles (800 kilometers) of the territory.
- Signal 8 is the one that matters: it means sustained wind of 39 to 73 miles per hour (63 to 117 km/h), and it closes schools, offices and most public transport. Signal 10 means hurricane force, 73 miles per hour or above (118 km/h and up).
- Two monsoons, opposite coasts: the southwest monsoon soaks the west-facing Andaman coast in the middle of the year, and the northeast monsoon soaks the east-facing coasts from December into March. Phuket and Ko Samui are wet at opposite ends of the calendar.
- Indonesia is simpler: official Indonesian tourism guidance puts the dry season from April to October and the wet season from November to March for Java and Bali. Bali is a wet-season port in January, not a washed-out one.
Why Japan’s typhoon peak lands in the middle of cruise season
Japan’s cruise season runs roughly from March into November, one of the longer windows on the calendar of regional cruise seasons, with a hole punched in the middle of it. The hole is August and September.
Landfall is the figure that actually threatens a port call, and it peaks in September at 1.0 a year. A storm does not have to reach land to close a port, though, and that is the part most people miss.
Swell runs ahead of a typhoon by a day or more and travels a very long way. That is how you end up losing a Shikoku or Kyushu call on a morning that looks calm and blue from your balcony.
If you want the shape of the season without the storms, spring and late fall are where the itineraries are quietest. My regional overview of Japan cruise ports by region lays out which stops run in which months.
Hong Kong counts in numbers, and the numbers close the city
Hong Kong does not describe storms in adjectives. It describes them in a numbered signal, and the whole territory reacts to the number rather than to the forecast.
Signal 3 means sustained wind of 25 to 39 miles per hour (41 to 62 km/h) with gusts that can top 68 miles per hour (110 km/h). Outlying island ferries thin out and open-top sightseeing buses stop running, but the city keeps working.
Signal 8 is the one that empties the place. The Hong Kong Observatory defines it as sustained wind of 39 to 73 miles per hour (63 to 117 km/h) with gusts that may exceed 112 miles per hour (180 km/h), and it shuts schools, offices and most transport.
Signal 9 means the gale is increasing significantly, and Signal 10 means hurricane force, sustained at 73 miles per hour or more (118 km/h and above). If a 10 looks even faintly possible, your ship will have sailed long before it goes up.
The practical version for a cruiser is simple. At Signal 3 you shorten your plans, and at Signal 8 you are not going ashore at all, which is worth knowing before you prepay a Victoria Peak tram tour in my Hong Kong cruise port guide.
The two monsoons that make Phuket and Ko Samui trade places
Southeast Asia does not have a rainy season. It has two of them, and they sit on opposite coasts of the same narrow peninsula.
The southwest monsoon drives wet, swelly weather onto the west-facing Andaman coast through the middle of the year, which is Phuket, Langkawi and Penang. That is also when tender operations at exposed Andaman anchorages start getting interesting.
The northeast monsoon then flips the map. The Malaysian Meteorological Department describes the northeast monsoon months as December to March, and says the exposed east coast of Peninsular Malaysia gets its maximum rainfall in November, December and January.
Ko Samui sits in the Gulf of Thailand and follows that east-coast pattern almost exactly. Its worst weeks are late in the year, at the same time the Andaman side is at its calmest.
So a January itinerary that calls at both Phuket and Ko Samui is going to get one of them right and one of them wrong. That is not bad luck, it is geography, and you can see it coming a year out from my Phuket cruise port guide.
Bali, Ha Long Bay and the rest of the calendar
Indonesia keeps things simpler than the rest of the region. The official Indonesian tourism portal puts the dry season from April to October and the wet season from November to March across Java and Bali.
Benoa in January is a very different port from Benoa in July, but the difference is mostly afternoon thunderstorms rather than all-day rain. Temple visits and rice terrace drives still work; it is the wet-afternoon traffic that actually ruins a plan.
Northern Vietnam is its own animal, because Ha Long Bay gets summer typhoons and a cool, misty winter. Local authorities suspend tourist boat operations in bad weather, and I have watched February fog do that as effectively as September wind.
What a reroute actually looks like from your cabin
The first sign is usually the daily program, not an announcement. Two ports swap places, or a sea day quietly appears where a call used to be.
What you are owed is where the romance ends. Royal Caribbean states that it may, at any time and without prior notice, cancel, advance, postpone or deviate from any scheduled sailing or port of call, and that it is not required to refund any portion of fare or make any compensation when it does.
Every major line publishes a version of the same clause, the same one that governs itinerary changes in Atlantic hurricane season, so treat compensation as goodwill rather than a right. What normally comes back automatically is that port’s taxes and fees, credited to your onboard account.
The things I would actually do
- Pick the month before the ship: in Asia the calendar does more work than the hardware. A quiet October ship in a good week beats a spectacular one in the middle of September.
- Read the coast, not the country: Thailand has two opposite rainy seasons and Malaysia has two coasts that behave differently. Look up the specific port, not the nation.
- Watch the national agency, not an app: the Japan Meteorological Agency for Japan and the Hong Kong Observatory for Hong Kong publish the actual warnings your ship is reacting to. Consumer apps lag them by hours.
- Leave a real buffer around the cruise: typhoons close airports as readily as ports, and a same-day flight home in September is optimistic. Two nights on each end is not paranoia in Asia, it is arithmetic.
- Do not prepay a nonrefundable private tour in peak weeks: in August and September I book guides who take payment on the day. The premium for that flexibility is small compared with the loss.
Fun fact: Hong Kong’s No. 8 signal comes in four flavors, 8 Northeast, 8 Southeast, 8 Southwest and 8 Northwest, and the compass point tells you which quadrant the gale is blowing from rather than how hard. All four cover the same sustained wind band, so a switch from 8 Northeast to 8 Southwest is a wind shift, not an escalation.
How I would actually decide
If Japan is the point of the trip, I would book late March through May, or October into early November, accepting that blossom and foliage dates are a gamble. Those windows dodge both the June rains and the August storms, and they are when the country looks its best anyway.
If Southeast Asia is the point, I would sail between December and March and accept that the Gulf of Thailand side may be soggy. That season is the regional norm for a reason, and the sea state is far kinder than it is mid-year.
If price is the point, August and September are cheap for exactly the reason you think. I have had wonderful late-summer sailings in Asia, and I have also had one where we saw three of six scheduled ports.
A realistic word on accessibility
Asia has more tender ports than most people expect, and monsoon swell is what turns a tender day into a cancelation. Ko Samui, Phuket and several Japanese island calls are tender operations in normal conditions.
Tendering is where mobility problems become trip-defining rather than inconvenient. A moving platform, a step down and a wet deck are hard on a good day and impossible in a leftover swell.
Most lines will not load a wheelchair user into a tender when the sea is marginal, and that decision belongs to the officer at the shell door. My explainer on what happens when rough seas delay or cancel tendering covers how that call gets made.
If tendering matters to you, favor itineraries built on alongside berths. Yokohama, Kobe, Singapore, Hong Kong and Port Klang are all walk-off ports in ordinary weather.
When to go, and the weather
Japan in April sits in the 50s and 60s Fahrenheit with blossom and a fair amount of rain. October and November run in the 60s and low 70s and are the most reliably pleasant weeks of the year.
Japanese summer is the trap. July and August bring highs in the 90s with humidity to match, and that is before you factor in the storms.
Southeast Asia barely changes temperature at all. Expect highs in the high 80s and low 90s Fahrenheit in Singapore, Bali, Phuket and Penang in every month, with the rain rather than the thermometer marking the seasons.
Quick answers
When is typhoon season in Asia?
The western North Pacific produces storms all year, but the risk to a cruise runs from July through October. Japan Meteorological Agency normals put formation at its highest in August and landfalls at their highest in September.
Will my cruise be canceled because of a typhoon?
The whole sailing almost never is. What changes is the port list, and lines reserve a very broad right to reorder, shorten or drop calls without notice or compensation.
What does a Signal 8 mean for my Hong Kong port day?
It means you are staying on the ship, assuming the ship is even still there. Signal 8 covers sustained wind of 39 to 73 miles per hour (63 to 117 km/h) and closes schools, offices and most transport across the territory.
Is Phuket or Ko Samui better in January?
Phuket, comfortably. January falls in the northeast monsoon, which soaks the Gulf of Thailand coast while the Andaman side is at its driest.
Should I avoid Bali in the wet season?
No, but adjust your expectations. Indonesian tourism guidance puts the wet season from November to March, and in Bali that usually means heavy afternoon storms rather than a lost day.
The last word
Asia rewards people who book by the calendar and punishes people who book by the photograph. The photographs were all taken in the dry season, on the correct coast, which is a detail the brochure never mentions.
If you want to know which stops are structurally fragile before you commit, my roundup of the cruise ports most likely to be missed or canceled is the companion piece to this one. Several of them are in this region, and most of them are tender calls.
Book the shoulder months, keep the last day loose, and stop reading the storm track twelve times an hour. The bridge is watching the same charts you are, with better data and a much stronger motive to get you to the next port.
How this guide was researched: Unless a first-hand visit is explicitly identified above, this guide is based on independent research using official port, tourism, transit, government, and attraction sources where available. Typhoon frequency was checked against the Japan Meteorological Agency’s 1991 to 2020 typhoon statistics, warning signal criteria against the Hong Kong Observatory’s tropical cyclone warning signals leaflet, monsoon timing against the Malaysian Meteorological Department and the official Indonesian tourism portal, and itinerary change policy against Royal Caribbean’s published passenger information. Logistics and time-sensitive details were reviewed in August 2026. See our Editorial Policy.
More on this topic: browse every guide on weather, crowds and conditions.
