Monthly climate guide
Kumamoto weather in September
September in Kumamoto is typically hot, with average daytime highs around 27°C (81°F) and night-time lows near 19°C (67°F). The month usually brings about 233 mm of rain (very wet) and is often cloudy. Daytime highs are 3°C cooler than August and 5°C warmer than October.
What stands out in September
- September brings early autumn to Kumamoto.
- September is Kumamoto's third warmest month.
- Kumamoto is usually about 2°C warmer than Hiroshima, 240 km away, in September.
- It's humid — around 84% — so the heat feels heavier.
Avg high
27°C
81°F
Avg low
19°C
67°F
Rainfall
233 mm
very wet
Humidity
84%
relative
Sky
67%
cloud · often cloudy
Kumamoto weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | 9°C / 48°F | 1°C / 33°F | 64 mm | 80% | 65% |
| February | 10°C / 51°F | 1°C / 35°F | 101 mm | 79% | 65% |
| March | 14°C / 57°F | 4°C / 40°F | 125 mm | 78% | 61% |
| April | 19°C / 66°F | 9°C / 48°F | 152 mm | 78% | 62% |
| May | 24°C / 75°F | 14°C / 56°F | 159 mm | 78% | 66% |
| June | 26°C / 79°F | 18°C / 65°F | 437 mm | 85% | 83% |
| July | 30°C / 85°F | 23°C / 73°F | 423 mm | 85% | 72% |
| August | 31°C / 87°F | 23°C / 74°F | 238 mm | 83% | 62% |
| September | 27°C / 81°F | 19°C / 67°F | 233 mm | 84% | 67% |
| October | 22°C / 72°F | 14°C / 57°F | 135 mm | 82% | 54% |
| November | 17°C / 63°F | 8°C / 47°F | 93 mm | 82% | 56% |
| December | 11°C / 51°F | 3°C / 37°F | 80 mm | 80% | 64% |
What to pack for September
- Light, breathable clothing (cotton or linen)
- A sun hat and high-SPF sunscreen
- A refillable water bottle
- A compact umbrella or packable rain jacket
- Water-resistant shoes
- Quick-dry fabrics — it feels stickier than the temperature suggests
Is September a good time to visit Kumamoto?
Compare the months in the chart above to find your ideal window.
Best time to visit Kumamoto →Other Japan cities in September
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Kumamoto weather in September. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/japan/kumamoto/september
<a href="https://weathercompare.eu/weather/japan/kumamoto/september">Kumamoto weather in September</a> (WeatherCompare)
<iframe src="https://weathercompare.eu/embed/japan/kumamoto" width="300" height="160" style="border:0;border-radius:12px" loading="lazy" title="Kumamoto weather in September"></iframe> <p style="font-size:12px"><a href="https://weathercompare.eu/weather/japan/kumamoto/september">Kumamoto weather in September</a> – WeatherCompare</p>
Kumamoto in September: quick answers
Is September a good time to visit Kumamoto?
September is one of the wetter months in Kumamoto, with about 233 mm of rain. You can still go: pack a rain jacket and keep plans flexible.
How warm is Kumamoto in September?
Average highs are about 27°C (81°F) and average lows about 19°C (67°F), based on 10 years of daily data.
Does it rain a lot in Kumamoto in September?
Kumamoto typically gets around 233 mm of rain in September — very wet.
Figures are long-term averages for the area around Kumamoto (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.