Monthly climate guide
Nagasaki weather in September
Expect hot weather in Nagasaki in September: afternoons reach about 27°C (81°F), while nights drop to around 20°C (69°F). Around 227 mm of rain falls over the month (very wet), and skies are often cloudy. Daytime highs are 4°C cooler than August and 5°C warmer than October.
What stands out in September
- Temperatures are falling — expect highs around 5°C lower by October.
- September is Nagasaki's third warmest month.
- It's humid — around 84% — so the heat feels heavier.
- September brings early autumn to Nagasaki.
Avg high
27°C
81°F
Avg low
20°C
69°F
Rainfall
227 mm
very wet
Humidity
84%
relative
Sky
68%
cloud · often cloudy
Nagasaki weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | 9°C / 49°F | 3°C / 37°F | 66 mm | 78% | 84% |
| February | 11°C / 51°F | 3°C / 38°F | 99 mm | 78% | 79% |
| March | 14°C / 58°F | 6°C / 43°F | 124 mm | 77% | 73% |
| April | 19°C / 66°F | 10°C / 50°F | 162 mm | 78% | 69% |
| May | 24°C / 74°F | 15°C / 58°F | 164 mm | 79% | 68% |
| June | 26°C / 79°F | 19°C / 66°F | 378 mm | 85% | 82% |
| July | 30°C / 85°F | 23°C / 74°F | 370 mm | 86% | 69% |
| August | 31°C / 88°F | 24°C / 76°F | 252 mm | 83% | 59% |
| September | 27°C / 81°F | 20°C / 69°F | 227 mm | 84% | 68% |
| October | 22°C / 72°F | 15°C / 59°F | 133 mm | 81% | 60% |
| November | 17°C / 63°F | 10°C / 51°F | 105 mm | 80% | 71% |
| December | 11°C / 52°F | 5°C / 41°F | 90 mm | 79% | 84% |
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 Nagasaki?
Compare the months in the chart above to find your ideal window.
Best time to visit Nagasaki →Other Japan cities in September
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Nagasaki weather in September. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/japan/nagasaki/september
<a href="https://weathercompare.eu/weather/japan/nagasaki/september">Nagasaki weather in September</a> (WeatherCompare)
<iframe src="https://weathercompare.eu/embed/japan/nagasaki" width="300" height="160" style="border:0;border-radius:12px" loading="lazy" title="Nagasaki weather in September"></iframe> <p style="font-size:12px"><a href="https://weathercompare.eu/weather/japan/nagasaki/september">Nagasaki weather in September</a> – WeatherCompare</p>
Nagasaki in September: quick answers
Is September a good time to visit Nagasaki?
September is one of the wetter months in Nagasaki, with about 227 mm of rain. You can still go: pack a rain jacket and keep plans flexible.
How warm is Nagasaki in September?
Average highs are about 27°C (81°F) and average lows about 20°C (69°F), based on 10 years of daily data.
Does it rain a lot in Nagasaki in September?
Nagasaki typically gets around 227 mm of rain in September — very wet.
Figures are long-term averages for the area around Nagasaki (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.