September 11 sees frequent showers in Jeju Island. Historical data shows a 46% chance of rain, so pack accordingly. Temperatures average 26°C. Jeju Island is currently in its most popular travel window, meaning vibrant crowds and premium pricing.
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Essential Travel Info for Jeju Island
Currency
KRW
₩ South Korean won
Language
Korean
Driving
Right side
Safety
High Safety
GPI: 1.779
Jeju Island Weather Forecast for September 11
"Warm & Sunny. Expect average highs of 26.4°C. 46% chance of rain."
What to Wear in Jeju Island in September
Based on historical data for September 11, Jeju Island typically experiences temperatures between 22.8°C and 26.4°C. We recommend packing t-shirt, light clothing, umbrella to stay comfortable. With a 46% chance of rain, keeping a raincoat or umbrella handy is a smart move.
Complete Packing Guide
Weekly breakdown & essential items for Jeju Island
Smart Suitcase
- T-Shirt
- Light Clothing
- Umbrella
Average High
26.4°C
Daytime Peak
Average Low
22.8°C
Nighttime Low
Feels Like
27.7°C
☀️ Minor difference
Rain Chance
46%
Avg 4mm if it rains
Cloud Cover
65%
Overcast
Pressure
1012.7 hPa
Low volatility
Jeju Island Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
✓ Weather is generally predictable, but pack for minor variations. A light backup layer is recommended.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 15 for extended outdoor time
Type I-II
🔴 30 min to burn
Type III-IV
🟡 45 min to burn
Type V-VI
🟢 75 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
23.5°C
Humid/Sticky
Heat Stress
Low
No heat warning
😐 Best outdoor time:
Morning hours (before 11 AM)
Marine Conditions
Jellyfish Warning
High water temps may attract jellyfish swarms.
Swim Index
✅ Excellent Swimming Conditions
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in South Korea
Flight Traffic
High
95/100 pressure index
Health Advisory
Required
2 vaccines • View Details →
Landing Slots
~234
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Jeju Island
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
06:15
☀️ Noon
12:32
🌇 Sunset
18:48
⏱️ Daylight
12h 33m
Wind Speed
14.4 km/h
Gentle breeze
Sunshine
8.0 hrs
Direct Sun (Cloud-free)
Humidity
84%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Jeju Island
Smart Flight Estimator
Airport-to-Airport Logistics
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Add your home location in settings to see airport details.
Travel Health & Safety in Jeju Island
Travel Comfort Index
Real-time tourism conditions
Weather Quality
⛅ Good
Tourist Crowds
🟡 Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Stable conditions. Low risk of headaches.
Mild discomfort possible for arthritic conditions.
Moderate fish activity expected.
Air quality is excellent. Perfect for outdoor activities.
Regional Safety Profile
Seismic Activity
Rare minor tremors. Buildings are earthquake-resistant.
Typhoon Risk
Year-round risk present
Travel Alert: This region has elevated natural risks. We recommend registering with your embassy and keeping emergency numbers handy.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, Jeju Island on September 11 averages 26.4°C with a 46% precipitation probability. Wedding/Outdoor Event Score: 83/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Jeju Island Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
September 7
26.7°C • 36% rain
Score
89
September 8
26.5°C • 36% rain
Score
89
September 9
26.5°C • 36% rain
Score
89
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (September 11) in other destinations
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📍 Is Jeju Island Worth Visiting on September 11?
Planning a trip to Jeju Island on September 11? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year typically offers vibrant summer conditions averaging 26.4°C with a 46% historical precipitation risk.
✈️ Travel Logistics: Approximately 234 landing slots available daily during this period, indicating manageable crowd levels.
💉 Health Advisory: 10 vaccinations are recommended for South Korea, including COVID-19.
🌊 Coastal Conditions: Water temperature averages 29.3°C (hot soup). Wave conditions are generally fun waves with heights around 0.76m.
📊 Historical Extremes: The hottest September 11 recorded in the last 30 years saw temperatures hit 30.3°C in 2024, while the coldest dropped to 20.4°C in 2018.