September 25 is generally a great time to visit Jeju Island. While there is a slight chance of rain (22%), showers are usually brief. Expect comfortable 24°C weather. As it's peak season for Jeju Island, we recommend booking your stay well in advance to secure the best rates.
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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 25
"Mild & Comfortable. Expect average highs of 24.2°C. 22% chance of rain."
What to Wear in Jeju Island in September
Based on historical data for September 25, Jeju Island typically experiences temperatures between 20.7°C and 24.2°C. We recommend packing t-shirt, light clothing to stay comfortable. Trends suggest it will stay mostly dry (22% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for Jeju Island
Smart Suitcase
- T-Shirt
- Light Clothing
Average High
24.2°C
Daytime Peak
Average Low
20.7°C
Nighttime Low
Feels Like
25°C
☀️ Feels accurate
Rain Chance
22%
Avg 1.3mm if it rains
Cloud Cover
59%
Light drizzle
Pressure
1015.6 hPa
Low volatility
Jeju Island Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 98% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
06:00 - 10:00
16:00 - 18:00
Type I-II
🔴 27 min to burn
Type III-IV
🟡 41 min to burn
Type V-VI
🟢 68 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
20.3°C
Humid/Sticky
Heat Stress
Low
No heat warning
🙂 Best outdoor time:
Any time during daylight hours
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
06:24
☀️ Noon
12:27
🌇 Sunset
18:29
⏱️ Daylight
12h 4m
Wind Speed
17 km/h
Gentle breeze
Sunshine
8.3 hrs
Direct Sun (Cloud-free)
Humidity
79%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Jeju Island
Smart Flight Estimator
Airport-to-Airport Logistics
unlock smart flight estimates
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
☀️ Excellent
Tourist Crowds
🟡 Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Stable conditions. Low risk of headaches.
Weather unlikely to affect joint pain.
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 25 averages 24.2°C with a 22% precipitation probability. Wedding/Outdoor Event Score: 97/100."
— 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
Compare Other Cities
Same date (September 25) in other destinations
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📍 Is Jeju Island Worth Visiting on September 25?
Planning a trip to Jeju Island on September 25? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year is characterized by pleasant mild weather averaging 24.2°C with a 22% 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 27.8°C (tropical bath). Wave conditions are generally fun waves with heights around 0.95m.
📊 Historical Extremes: The hottest September 25 recorded in the last 30 years saw temperatures hit 29.3°C in 2025, while the coldest dropped to 15.9°C in 2019.