Overview
Jeju is in South Korea. The figures below are long-term monthly averages (2014-2023), not a forecast.
- Warmest month: August, with daytime highs around 29°C.
- Coolest month: January, with daytime highs around 8°C.
- Driest month: February, about 74 mm of rain.
- Wettest month: September, about 359 mm of rain.
- Sunniest month: August, about 9.9 hr of sunshine per day.
- Warmest sea: August, around 27°C.
Best months by holiday type
- Beach (warm air and sea)
- July, August, and September
Judged by simple climate rules applied to the monthly averages, not by local knowledge.
Climate by month
| Month | Day high | Night low | Sea | Rain (mm) | Rainy days | Sun (h/day) | Humidity | Wind (km/h) |
|---|---|---|---|---|---|---|---|---|
| January | 8°C | 3°C | 15°C | 88 mm | 12 | 5.5 | 74% | 15 km/h |
| February | 9°C | 3°C | 14°C | 74 mm | 10 | 6.5 | 72% | 15 km/h |
| March | 13°C | 7°C | 14°C | 112 mm | 11 | 8.0 | 73% | 13 km/h |
| April | 17°C | 11°C | 15°C | 130 mm | 10 | 8.8 | 75% | 12 km/h |
| May | 21°C | 15°C | 17°C | 148 mm | 11 | 9.4 | 75% | 11 km/h |
| June | 24°C | 19°C | 20°C | 205 mm | 13 | 8.2 | 85% | 10 km/h |
| July | 28°C | 24°C | 25°C | 251 mm | 18 | 8.4 | 87% | 11 km/h |
| August | 29°C | 25°C | 27°C | 270 mm | 17 | 9.9 | 84% | 11 km/h |
| September | 25°C | 21°C | 25°C | 359 mm | 17 | 7.5 | 83% | 13 km/h |
| October | 20°C | 16°C | 22°C | 153 mm | 10 | 8.2 | 77% | 13 km/h |
| November | 16°C | 10°C | 19°C | 87 mm | 10 | 6.6 | 76% | 12 km/h |
| December | 10°C | 5°C | 17°C | 86 mm | 13 | 5.2 | 74% | 16 km/h |
Similar destinations
Data and sources
- Air climate: Open-Meteo Historical Weather API (ERA5 / ERA5-Land reanalysis), 2014-2023. CC BY 4.0 (Open-Meteo); underlying ERA5 data: Copernicus licence
- Sea temperature: NOAA Coral Reef Watch CoralTemp v3.1 monthly SST (5 km), 2014-2023.
- Last updated October 8, 2026.