October 21 is statistically one of the best days of the year in Seoul. With minimal rain risk (8%) and pleasant highs of 18°C, it's ideal for outdoor adventures. Seoul is currently in its most popular travel window, meaning vibrant crowds and premium pricing.
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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 October 21
"Mild & Comfortable. Expect average highs of 17.8°C. 8% chance of rain."
What to Wear in Seoul in October
Based on historical data for October 21, Seoul typically experiences temperatures between 7.9°C and 17.8°C. We recommend packing light jacket, long pants to stay comfortable. Trends suggest it will stay mostly dry (8% 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
17.8°C
Daytime Peak
Average Low
7.9°C
Nighttime Low
Feels Like
17.8°C
🌤️ Feels accurate
Rain Chance
8%
Avg 0.3mm if it rains
Cloud Cover
42%
Overcast
Pressure
1021.1 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 96% 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
🔴 47 min to burn
Type III-IV
🟡 71 min to burn
Type V-VI
🟢 118 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
13.1°C
Pleasant
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
~1,053
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Seoul
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
06:46
☀️ Noon
12:17
🌇 Sunset
17:49
⏱️ Daylight
11h 2m
Wind Speed
11.4 km/h
Light breeze
Sunshine
8.2 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
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
☀️ Excellent
Tourist Crowds
🟡 Busy
Price Level
💰💰 Moderate
Health & Wellbeing
Meteo-Health Forecast
Moderate fluctuations. Some sensitivity possible.
Weather unlikely to affect joint pain.
High pressure may reduce activity.
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 October 21 averages 17.8°C with a 8% precipitation probability. Wedding/Outdoor Event Score: 98/100."
— 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
October 15
18.7°C • 14% rain
Score
100
October 16
18.5°C • 15% rain
Score
100
October 17
18.2°C • 12% rain
Score
99
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (October 21) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Seoul Worth Visiting on October 21?
Planning a trip to Seoul on October 21? 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 17.8°C with a 8% historical precipitation risk.
✈️ Travel Logistics: Approximately 1,053 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 October 21 recorded in the last 30 years saw temperatures hit 21.7°C in 2019, while the coldest dropped to 4.3°C in 2023.