Ishigaki (Yaeyama) weather in September
September in Ishigaki: sweltering, soaked, with clean air — fine if you can take 18 rainy days.
Updated September 2026 · climate normals from ERA5 reanalysis
#9 of 12 months in Ishigaki · #964 of 1413 destinations to visit in September · comfort 69/100 (tier C)
- Days
- 31°C
- Nights
- 26°C
- Wet days
- 18
- Sun
- 9.6 h
- Humidity
- 81%
- Daylight
- 12 h
Traveller notes on Ishigaki in September
Other months in Ishigaki
Okinawa-region forum posters generally rate October favorably: it's past the subtropical rainy season and still warm enough for snorkeling, with early October running noticeably warmer than the tail end of the month. The consistent caveat is typhoons - October is technically the winding-down edge of the season, and while the odds of a direct hit drop compared to July through September, posters were clear the risk doesn't disappear entirely, so it's worth checking storm tracking before a trip. Expect warm, humid days rather than anything close to cool.
Forum posters describe April as statistically stable and pleasant, sitting before the rainy season and well ahead of typhoon risk - one local source specifically names April (alongside June) as a genuinely good window for that reason. Sea temperatures run around 20-23C, described by posters as fine for tide-pooling and general exploring but on the cool side for comfortable swimming without a wetsuit. The clear trade-off for visiting before peak season: posters report noticeably lower accommodation costs (some citing roughly half of high-season rates), thinner crowds, and especially clear water for snorkeling and diving even without the warmer swimming temperatures summer brings.
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Ishigaki climate normals — September
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Ishigaki in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Shoulder seasonschool holidays in 3 of the markets that fill it, an ordinary month(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Ishigaki's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherIshigaki's best weather comes in April, June and July — separate windows, not one continuous season.
Best weatherFair weatherToughest weather
What's on in Ishigaki in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Nature
Manta season at Kabira
1 Jun – 30 Nov · usuallyDive seasonBook earlyThe cleaning stations off Kabira draw mantas through the second half of the year, with the best odds from August to October. Boats are capped and the good operators fill a season ahead. Source ↗
- Hazard
Typhoon season
1 Jul – 15 Oct · usuallyClosuresThe Yaeyamas sit in the busiest track in Japan. The ferries to Taketomi and Iriomote stop a day before anything arrives and restart a day after it leaves — budget slack at both ends of the trip. Source ↗
Nearby, and something's on
Within 300 km of Ishigaki — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Ishigaki?
Ishigaki in September — FAQ
- Is September a good time to visit Ishigaki?
- September in Ishigaki: sweltering, soaked, with clean air — fine if you can take 18 rainy days. It ranks #9 of 12 months for Ishigaki on SeasonMap's comfort score (69/100).
- What is the weather like in Ishigaki in September?
- In September, Ishigaki averages a daily high of 31.3°C and a low of 25.7°C, with about 248.8 mm of rain over roughly 18.2 rainy days.
- What is the air quality in Ishigaki in September?
- Ishigaki has a mean US Air Quality Index of about 32 in September.
Within 300 km: Miyakojima's Sea warm enough to swim around 1 Apr – 15 Nov, and Taipei's Ghost Month around 5 Aug – 15 Sep.