Typhoon Season and Intensity in Japan
Typhoon season in Japan runs from June through October, and the Japan Meteorological Agency (JMA, "the national weather service") publishes every official forecast, warning, and statistic residents need.1 This guide translates the season calendar and the domestic intensity ladder into resident decisions: when to watch, when to act, and what each label means for trains, flights, and daily plans.
Procedures, fees, and requirements can change. Confirm current details at the Japan Meteorological Agency site.
Overview
Japan's typhoon discussion centers on June through October, with August and September the most active months.2 Over the 1991 to 2020 normals period, about 3 typhoons a year made landfall, while roughly 12 approached without landing.2 Intensity labels run from tropical-storm strength up to the 猛烈な台風 (mōretsuna taifū, "violent typhoon") for the strongest systems.3
The Season Window
The calendar is lopsided. Early summer sees occasional approaches, autumn sees landfalls taper off, and the core of the season sits firmly in late summer.
June to October, peaking in August and September
Landfall normals concentrate in July (0.6), August (0.9), September (1.0), and October (0.3), with almost nothing outside June to October (as of 2026-09; confirm current figures with the Japan Meteorological Agency).2 Approaches show the same shape: 3.3 each in August and September against an annual 11.7 (as of 2026-09).2 About 25.1 tropical cyclones form each year across the western North Pacific in the normals period (as of 2026-09).2
Peak-month trips carry the highest disruption odds. A one-day buffer around key travel dates costs little and saves rebooking scrambles.2
How many reach Japan each year
The annual landfall normal is 3.0 (as of 2026-09; confirm current figures with the Japan Meteorological Agency).2 Recent years show the spread around that average: 3 landfalls in 2025, 2 in 2024, 3 each in 2022 and 2021, and 5 in the busy year of 2019 (as of 2026-09).4
JMA counts a landfall only when the storm center reaches the coast of Hokkaido, Honshu, Shikoku, or Kyushu.4 Brief crossings of small islands count as passage, not landfall, so yearly tables can look lower than headline storm counts.4
The JMA Intensity Ladder
JMA uses two label families. International-track bulletins step through Tropical Storm, Severe Tropical Storm, Typhoon, Very Strong Typhoon, and Violent Typhoon by wind speed in knots.1 Domestic announcements add the familiar 強い (tsuyoi, "strong"), 非常に強い (hijōni tsuyoi, "very strong"), and 猛烈な (mōretsuna, "violent") qualifiers once winds pass 33 m/s.3
| Domestic label | Max sustained wind | English-track band |
|---|---|---|
| (Typhoon, no qualifier) | 17 to 33 m/s | Tropical Storm to Typhoon |
| 強い (strong) | 33 to under 44 m/s | Typhoon |
| 非常に強い (very strong) | 44 to under 54 m/s | Very Strong Typhoon |
| 猛烈な (violent) | 54 m/s and up | Violent Typhoon |
The table above follows JMA's published thresholds.31 Size is labeled separately by the radius of the 15 m/s wind zone: 大型 (ōgata, "large") at 500 to 800 km and 超大型 (chō-ōgata, "super large") at 800 km and up.3 The zone of 25 m/s-plus winds is called the 暴風域 (bōfū-iki, "storm wind zone").3
Wind speed and central pressure as dual metrics
JMA bulletins pair maximum sustained wind (10-minute mean) with central pressure in hectopascals.31 Lower pressure generally accompanies stronger wind, and both numbers move together across updates.1 When a bulletin shows pressure falling and winds rising, the storm is organizing; when the reverse happens, it is weakening even if rain continues.1
What Intensity Means for Daily Life
Labels predict disruption more than danger. A merely strong typhoon on a direct urban track disrupts more lives than a violent one curving out to sea.
Transit disruption and planned suspension
JR operators suspend or reduce services ahead of severe weather, announcing affected sections and time windows in advance.5 A September 2026 heavy-rain forecast had JR East suspending Yamagata Shinkansen sections for a full day from the first train.6 Operators call this advance practice 計画運休 (keikaku-unkyū, "planned suspension"): the stop is deliberate and pre-announced, not a breakdown.7
Suspension notices typically appear the prior evening. Confirm your morning train before bed, not at the station.5
Flights, schools, and workplaces
Flight cancellations, school closures, and event cancellations cluster around landfall days.6 No single national rule sets them; each airline, school, and employer decides on its own thresholds.6 Expect the announcement wave the evening before, alongside the rail notices.6
Monitoring Official Forecasts
JMA is the authoritative issuer of typhoon position, track, and warning information.1 Start there, then layer convenience channels on top.
JMA and weather apps
JMA's tropical cyclone pages carry positions, predicted paths, and intensity forecasts in English.1 Alongside JMA, residents commonly check Tenki.jp, Yahoo Weather, and the NHK weather page for advisor-style presentation of the same official data. Track forecasts are most trustworthy from roughly two to three days out; treat earlier outlooks as trends to watch rather than plans to execute.
Multilingual alerts for foreign residents
The Safety Tips app pushes earthquake early warnings, tsunami warnings, and weather warnings in 15 languages including English.8 It also carries evacuation flowcharts and communication cards for asking nearby people for help.8 Separately, register your own municipality's advisory app or broadcast list, since evacuation orders come from the mayor, not from JMA.9
Good to know
A weak label does not mean weak rain
Wind labels describe wind. JMA dropped its old "weak" intensity wording decades ago partly because weak-labeled systems still killed through rain. Judge flood risk from rainfall forecasts and your hazard map, never from the wind adjective alone.
Track forecasts are reliable at 48 to 72 hours, not at seven days
Long-range cones shift substantially between updates. At seven days out, watch the trend; at two to three days, start deciding; inside 24 hours, execute the plan. Treat each new forecast as superseding the last.
Your municipality, not JMA, tells you to evacuate
JMA describes the storm; the mayor orders the evacuation.9 If you follow only national-track coverage, you will know the weather and miss the order. Municipal registration is the step that closes that gap.9
See also
- Calling 119: When and How
- Setting Up an Emergency Fund Adapted to Japan
- Fire Insurance and the Carrier-Substitution Trick
- Flooding in Japan: River, Inland, Pluvial, and Coastal