Jeju weather in September
September in Jeju: hot, soaked, with very humid — a good time to visit.
#9 of 12 months in Jeju · #501 of 604 destinations to visit in September · comfort 62/100 (tier C)
Updated June 2026 · climate normals from ERA5 reanalysis
Jeju climate normals — September
| Daytime high | 26°C / 79°F | 🥵 hot |
|---|---|---|
| Nighttime low | 23°C / 74°F | |
| Feels like (high) | 29°C / 84°F | |
| Rainfall | 318 mm / 12.5 in | ⛈ soaked |
| Rainy days | 15 days | |
| Humidity | 80% | 💦 very humid |
| Dew point | 21°C / 70°F | |
| Sunshine | 7.7 h/day | |
| Daylight | 12.4 h | |
| Wind | 26 km/h / 16 mph | |
| Air quality (US AQI) | 62 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Jeju in September — FAQ
- Is September a good time to visit Jeju?
- September in Jeju: hot, soaked, with very humid — a good time to visit. It ranks #9 of 12 months for Jeju on SeasonMap's comfort score (62/100).
- What is the weather like in Jeju in September?
- In September, Jeju averages a daily high of 25.9°C and a low of 23.2°C, with about 318.2 mm of rain over roughly 15 rainy days.
- What is the air quality in Jeju in September?
- Jeju has a mean US Air Quality Index of about 62 in September.