The month in detail
What to expect in September
Autumn in Jeju is often underrated: 79°F, golden light and declining crowds. An interesting window. With 46% of rainy days, always have indoor alternatives planned. A good balance between weather and crowds, even if May (7.9/10) remains theoretically better.
September ranks 3 out of 12 months in Jeju. Compared to August: −7°F daytime, 5 pts more rainy days, −1.7h of sun per day.
This month's conditions
What it's like in September
UV index
6 · high
sunscreen and hat advised
Feels like
muggy at times
20°
Sea
28°C
warm, ideal
Daylight
12.2h of daylight
Air quality
good
AQI 38
Compare
Is September the right month?
The best month in Jeju is May (7.9/10), 0.3 pt higher than September.
Book
Plan your trip
Hotels at their lowest outside peak season, highest on comfortable months. Shoulder seasons offer a good price/climate compromise.
Stay
Hotels & rentals · Jeju
Expedia →
Activities
Tours, tickets, experiences
See ↓
Flights
Multi-airline comparator
Kiwi →
🎟️ Activities & tours · Jeju
GetYourGuide selection · free cancellation
Practical info
What you need to know before you go
Three angles: the country (language, currency, safety, budget), the year-round climate, and the specifics of a beach trip.
Country · South Korea
🗣️LanguageKorean
💶CurrencySouth Korean Won (₩)
🚗DrivingRight-hand
🛡️Safety ⓘVery safe · 1/5
💰Cost of living ⓘModerate · 3/5
🌡️ Climate
🌍Climate typeTemperate oceanic
📈Climate trend ⓘStable
🔥Hottest monthAugust · 86°F
❄️Coolest monthJanuary · 46°F
🌧️Rainiest month ⓘSeptember · 46%
🏖️ Beach trip
📅Peak seasonJuin → Sept
🏖️Swell (Sept–Mar) ⓘModérée
Explore
Other destinations in September
If September doesn't convince you for this destination, compare with others.
Location
Where is Jeju ?
Global position + regional geographic context.
🌍 World
🔍 Geographic context
South KoreaTemperate oceanic climate with a 7.9 → 4.0 gap between best and worst month. 10 years of ERA5 data to choose by project.
33.50°N · 126.53°E
Questions
Frequently asked questions
What is the best time to visit Jeju?
May is the best month with 72°F highs, 59°F lows, 6.9h of sunshine and 26.0% rainy days. The months of May & June offer comparable conditions.
How many hours of sunshine does Jeju get in May?
Jeju averages 6.9 sunshine hours per day in May. It is the sunniest month with a climate score of 7.4/10.
What is the rainiest month in Jeju?
January is the most unfavourable month with January has the lowest climate score of the year and the lowest climate score of the year.
What are the temperatures at night in Jeju in May?
In May, overnight lows reach 59°F, while afternoon highs average 72°F.
Is Jeju good in winter?
In winter (December-February), Jeju scores 4.0/10 on average — Difficult period — prefer the peak season.. The best month overall remains May with a score of 7.4/10.
When should you avoid Jeju?
January is the most difficult month to visit Jeju, with January has the lowest climate score of the year. Climate conditions are at their lowest of the year during this period.
Can you swim in Jeju in September?
In September, the sea averages 82°F in Jeju: warm, ideal. Ideal conditions for swimming and snorkeling.
Do you need sun protection in Jeju in September?
The average UV index reaches 6 in September in Jeju (high), with about 12.2h of daylight. Sunscreen and hat advised.