Monthly climate guide
Jeju weather in September
September in Jeju is typically warm, with average daytime highs around 24°C (76°F) and night-time lows near 22°C (72°F). The month usually brings about 180 mm of rain (very wet) and is often cloudy. Daytime highs are 3°C cooler than August and 4°C warmer than October.
What stands out in September
- Rain is above Jeju's usual level, by about 42%.
- Only 2 months are warmer in Jeju than September.
- There's little difference between day and night (around 2°C).
- Nights stay warm, rarely below 22°C — air-conditioning helps.
Avg high
24°C
76°F
Avg low
22°C
72°F
Rainfall
180 mm
very wet
Humidity
80%
relative
Sky
68%
cloud · often cloudy
Jeju weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | 8°C / 47°F | 6°C / 43°F | 47 mm | 77% | 77% |
| February | 9°C / 48°F | 6°C / 43°F | 61 mm | 75% | 76% |
| March | 11°C / 52°F | 8°C / 47°F | 91 mm | 74% | 67% |
| April | 15°C / 58°F | 12°C / 53°F | 142 mm | 79% | 68% |
| May | 18°C / 64°F | 15°C / 60°F | 122 mm | 84% | 72% |
| June | 22°C / 71°F | 20°C / 67°F | 179 mm | 89% | 82% |
| July | 26°C / 78°F | 24°C / 75°F | 195 mm | 90% | 74% |
| August | 28°C / 82°F | 26°C / 79°F | 243 mm | 84% | 66% |
| September | 24°C / 76°F | 22°C / 72°F | 180 mm | 80% | 68% |
| October | 20°C / 69°F | 18°C / 64°F | 106 mm | 74% | 59% |
| November | 16°C / 60°F | 13°C / 56°F | 88 mm | 74% | 68% |
| December | 11°C / 51°F | 8°C / 46°F | 63 mm | 76% | 77% |
What to pack for September
- T-shirts plus a light layer for the evening
- Comfortable trainers or sandals for long walks
- A compact umbrella or packable rain jacket
- Water-resistant shoes
Is September a good time to visit Jeju?
Compare the months in the chart above to find your ideal window.
Best time to visit Jeju →Other South Korea cities in September
Cite or embed this data
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Jeju weather in September. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/south-korea/jeju/september
<a href="https://weathercompare.eu/weather/south-korea/jeju/september">Jeju weather in September</a> (WeatherCompare)
<iframe src="https://weathercompare.eu/embed/south-korea/jeju" width="300" height="160" style="border:0;border-radius:12px" loading="lazy" title="Jeju weather in September"></iframe> <p style="font-size:12px"><a href="https://weathercompare.eu/weather/south-korea/jeju/september">Jeju weather in September</a> – WeatherCompare</p>
Jeju in September: quick answers
Is September a good time to visit Jeju?
September is one of the wetter months in Jeju, with about 180 mm of rain. You can still go: pack a rain jacket and keep plans flexible.
How warm is Jeju in September?
Average highs are about 24°C (76°F) and average lows about 22°C (72°F), based on 10 years of daily data.
Does it rain a lot in Jeju in September?
Jeju typically gets around 180 mm of rain in September — very wet.
Figures are long-term averages for the area around Jeju (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.