September 18 is generally a great time to visit Seoul. While there is a slight chance of rain (33%), showers are usually brief. Expect comfortable 25°C weather. Expect a bustling atmosphere in Seoul right now—this is when the city truly comes alive with visitors.
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Essential Travel Info for Seoul
Currency
KRW
₩ South Korean won
Language
Korean
Driving
Right side
Connect
Internet cafes known asPC bang(PC 방) (pr...
Safety
High Safety
GPI: 1.779
Seoul Weather Forecast for September 18
"Mild & Comfortable. Expect average highs of 24.8°C. 33% chance of rain."
What to Wear in Seoul in September
Based on historical data for September 18, Seoul typically experiences temperatures between 17°C and 24.8°C. We recommend packing t-shirt, light clothing, umbrella to stay comfortable. With a 33% chance of rain, keeping a raincoat or umbrella handy is a smart move.
Complete Packing Guide
Weekly breakdown & essential items for Seoul
Smart Suitcase
- T-Shirt
- Light Clothing
- Umbrella
Average High
24.8°C
Daytime Peak
Average Low
17°C
Nighttime Low
Feels Like
25.7°C
☀️ Feels accurate
Rain Chance
33%
Avg 4.3mm if it rains
Cloud Cover
59%
Overcast
Pressure
1013.2 hPa
Medium volatility
Seoul Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 95% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 15 for extended outdoor time
Type I-II
🔴 29 min to burn
Type III-IV
🟡 44 min to burn
Type V-VI
🟢 73 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
20.7°C
Humid/Sticky
Heat Stress
Low
No heat warning
🙂 Best outdoor time:
Any time during daylight hours
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in South Korea
Flight Traffic
High
92/100 pressure index
Health Advisory
Required
2 vaccines • View Details →
Landing Slots
~1,054
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Seoul
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
06:17
☀️ Noon
12:27
🌇 Sunset
18:38
⏱️ Daylight
12h 21m
Wind Speed
13 km/h
Gentle breeze
Sunshine
7.7 hrs
Direct Sun (Cloud-free)
Humidity
78%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Seoul
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 Seoul
Travel Comfort Index
Real-time tourism conditions
Weather Quality
⛅ Good
Tourist Crowds
🟡 Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Moderate fluctuations. Some sensitivity possible.
Weather unlikely to affect joint pain.
Moderate fish activity expected.
Unhealthy for sensitive groups. Consider wearing a mask outdoors.
Regional Safety Profile
Seismic Activity
Zero seismic activity detected in 30 years.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, Seoul on September 18 averages 24.8°C with a 33% precipitation probability. Wedding/Outdoor Event Score: 94/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Seoul Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
September 23
23.7°C • 14% rain
Score
100
September 24
24°C • 12% rain
Score
100
September 25
24°C • 14% rain
Score
100
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (September 18) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Seoul Worth Visiting on September 18?
Planning a trip to Seoul on September 18? 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 24.8°C with a 33% historical precipitation risk.
✈️ Travel Logistics: Approximately 1,054 landing slots available daily during this period, indicating peak tourist activity.
💉 Health Advisory: 10 vaccinations are recommended for South Korea, including COVID-19.
📊 Historical Extremes: The hottest September 18 recorded in the last 30 years saw temperatures hit 31.6°C in 2022, while the coldest dropped to 14.4°C in 2019.