May 18 is generally a great time to visit Seoul. While there is a slight chance of rain (23%), showers are usually brief. Expect comfortable 23°C weather. It's a great middle-ground for visiting Seoul—enough activity to feel the pulse, but no overwhelming lines.
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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 May 18
"Mild & Comfortable. Expect average highs of 22.6°C. 23% chance of rain."
What to Wear in Seoul in May
Based on historical data for May 18, Seoul typically experiences temperatures between 12.3°C and 22.6°C. We recommend packing light jacket, long pants to stay comfortable. Trends suggest it will stay mostly dry (23% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for Seoul
Smart Suitcase
- Light Jacket
- Long Pants
Average High
22.6°C
Daytime Peak
Average Low
12.3°C
Nighttime Low
Feels Like
23°C
☀️ Feels accurate
Rain Chance
23%
Avg 1.4mm if it rains
Cloud Cover
58%
Overcast
Pressure
1010.1 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 93% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
05:00 - 10:00
16:00 - 19:00
Type I-II
🔴 15 min to burn
Type III-IV
🟡 23 min to burn
Type V-VI
🟢 38 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
17.7°C
Noticeable
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
Moderate
43/100 pressure index
Health Advisory
Required
2 vaccines • View Details →
Landing Slots
~493
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Seoul
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:22
☀️ Noon
12:29
🌇 Sunset
19:37
⏱️ Daylight
14h 15m
Wind Speed
15.3 km/h
Gentle breeze
Sunshine
9.7 hrs
Direct Sun (Cloud-free)
Humidity
74%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Seoul
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 Seoul
Travel Comfort Index
Real-time tourism conditions
Weather Quality
☀️ Excellent
Tourist Crowds
🟡 Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Moderate fluctuations. Some sensitivity possible.
Mild discomfort possible for arthritic conditions.
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 May 18 averages 22.6°C with a 23% precipitation probability. Wedding/Outdoor Event Score: 97/100."
— 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
May 21
23.4°C • 16% rain
Score
100
May 23
23.8°C • 14% rain
Score
100
May 12
21.8°C • 19% rain
Score
99
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (May 18) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Seoul Worth Visiting on May 18?
Planning a trip to Seoul on May 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 22.6°C with a 23% historical precipitation risk.
✈️ Travel Logistics: Approximately 493 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 May 18 recorded in the last 30 years saw temperatures hit 26.8°C in 2020, while the coldest dropped to 10°C in 2025.