Mud festival in South Korea
In July, the peaceful seaside town of Boryeong turned into a chaos of mud for 9 days. We recommend putting this festival on your bucket list.
Jeju Weather in September
September in Jeju brings high temperatures around 26°C (79°F) during the day, dropping to 22°C (72°F) at night, and as part of the rainy season, heavy rainfall is common.
Rainfall in Jeju in September
As part of the rainy season, Jeju sees around 11 days of rain in September, with an average of 178 mm (7 in). Rainy season showers here are typically intense, often clearing quickly but coming down hard while they last.
Temperature in Jeju in September
Daytime temperatures in Jeju reach 26°C (79°F) in September, dropping to 22°C (72°F) at night. During September, the summer season is in full swing. The days can feel warmer than the evenings, so packing for both parts of the day is a good idea. At 22°C (72°F) overnight, nights are warm enough to sit outside comfortably in light clothing.
Sunshine in Jeju in September
The month brings about 162 hours of sunlight, offering a comfortable mix of sun and rainy moments.If your ideal day consists of dry skies and pleasant temperatures, October typically offers the best circumstances for Jeju.
Jeju Temperature in September
Min Temperature
22°C (72°F)
Max Temperature
26°C (79°F)
Chance of Rain
36%
Precipitation
178 mm (7 in)
Rainy days
11 days
Humidity
73%
Sunshine
162 hours
Percentage Sunshine
Jeju Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Jeju - and find the best time to visit.
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Jeju typically drop from around 28°C (82°F) at the start of September to approximately 24°C (75°F) by the end. Nights are warm, with lows typically ranging from 18°C (64°F) to 23°C (73°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather records for Jeju in September
Browse day-by-day weather records for Jeju spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Jeju historical weather extremes in September
According to our 50 years of weather records for Jeju, the following extremes were recorded between 1976 and 2026.
- The hottest September day on record in Jeju reached 35°C (95°F) (September 3, 1985).
- Jeju experienced its chilliest September day on September 22, 1980, reaching only 19°C (66°F).
- The lowest overnight temperature recorded in September was 10°C (50°F) (September 23, 1980).
Best Places in South Korea in September
Find out more about the weather in South Korea and which places have the best travel conditions in this month. See all of South Korea in September →
perfect weather
pleasant
tolerable
unpleasant
poor
Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C (68°F) and 29°C (84°F) and not too much precipitation (less than 90 mm (3.5 in) a month).
What to Wear in Jeju in September
Warm temperatures in September make for comfortable sightseeing weather. Pack breathable fabrics like cotton shirts, knee-length shorts or skirts, and comfortable walking shoes. A thin long sleeve for indoor spaces is handy. Heavy rain is guaranteed, please bring a good poncho and waterproof everything! Bring sunglasses since you'll have some sunny periods throughout the month
What To Do in Jeju in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
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Swimming7/10 -
Cycling7/10 -
Walking7/10 -
Camping6/10 -
Outdoor sports7/10
Jeju 3-Day Forecast
More climate data for Jeju
Temperature Rainfall Sunshine Humidity
See the full Jeju climate overview or explore weather in South Korea.
Popular in September
Where to go in September - average daytime high across popular destinations.
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