What is the weather like in Seoul in September?

Expect temperatures between 17°C and 25°C with 24% average rain probability and about 8 hours of sunshine daily.

What is the weather like in Seoul in September?

Seoul in September scores 65/100 based on 30 years of climate data. Recommended for planning your trip.

Who should visit Seoul in September?

September in Seoul is ideal for: Outdoor enthusiasts, Cultural tourists, Honeymoon couples, Business travelers.

Seoul Weather in September | 30-Year Forecast

Avg High

25°C

Hottest around day 1

Avg Low

17°C

Coolest around day 30

Rainy Days

14days

24% avg rain chance

Sunshine

8hrs/day

Autumn season

Essential Travel Info for Seoul

🗓️ Best Time to Visit 📖 Travel Guide 🍴 Food Guide

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

Travel Intelligence

Exclusive flight analytics & health data for Seoul

Smart Flight Estimator

Airport-to-Airport Logistics

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Flight Connectivity Analysis

Airport traffic data & seasonal patterns

Major Hub

100/ 100

Traffic Index

Extremely busy airport

Peak Daily Arrivals

slots per day

Peak

Aug

Low

May

Monthly Traffic Distribution

561

Jan

573

Feb

542

Mar

497

Apr

493

May

1078

Jun

1050

Jul

1150

Aug

1054

Sep

1053

Oct

1028

Nov

655

Dec

Traffic Level

Low Season

Key Connections

Osaka Kansai (KIX)

Tokyo Narita (NRT)

Fukuoka (FUK)

Hong Kong Chek Lap Kok (HKG)

Bangkok Suvarnabhumi (BKK)

Health & Safety Advisory

CDC travel health recommendations

10 Recommendations

COVID-19

All eligible travelers should be up to date with their COVID-19 vaccines. Please seeYour COVID-19 Vaccinationfor more information.

Hepatitis A

Recommended for unvaccinated travelers one year old or older going to South Korea.Infants 6 to 11 months old should also be vaccinated against Hepatitis A. The dose does not count toward the routine 2-dose series.Travelers allergic to a vaccine component should receive a single dose of immune globulin, which provides effective protection for up to 2 months depending on dosage given.Unvaccinated travelers who are over 40 years old, are immunocompromised, or have chronic medical conditions planning to depart to a risk area in less than 2 weeks should get the initial dose of vaccine and at the same appointment receive immune globulin.

Hepatitis B

Recommended for unvaccinated travelers younger than 60 years old traveling to South Korea. Unvaccinated travelers 60 years and older may get vaccinated before traveling to South Korea.

Japanese Encephalitis

Recommended for travelers whoAre moving to an area with Japanese encephalitis to liveSpend long periods of time, such as a month or more, in areas with Japanese encephalitisFrequently travel to areas with Japanese encephalitisConsider vaccination for travelersSpending less than a month in areas with Japanese encephalitis but will be doing activities that increase risk of infection, such as visiting rural areas, hiking or camping, or staying in places without air conditioning, screens, or bed netsGoing to areas with Japanese encephalitis who are uncertain of their activities or how long they will be thereNot recommended for travelers planning short-term travel to urban areas or travel to areas with no clear Japanese encephalitis season.

Malaria

CDC recommends that travelers going to certain areas of South Korea take prescription medicine to prevent malaria. Depending on the medicine you take, you will need to start taking this medicine multiple days before your trip, as well as during and after your trip. Talk to your doctor about which malaria medication you should take.Transmission areasLimited to the months of March–December in rural areas in the northern parts of the provinces of Incheon (also spelled Inch’ŏn), Gangwon (also spelled Kangwŏn), and Gyeonggi (also spelled Kyŏnggi), including the demilitarized zone (DMZ)Drug resistanceNoneSpeciesP. vivax(100%)Recommended chemoprophylaxisAtovaquone-proguanil, chloroquine, doxycycline, mefloquine, primaquine5, or tafenoquine2Updated April 23, 2025See footnotes

Measles

Cases of measles are on the rise worldwide. Travelers are at risk of measles if they have not been fully vaccinated at least two weeks prior to departure, or have not had measles in the past, and travel internationally to areas where measles is spreading.All international travelers should be fully vaccinated against measles with the measles-mumps-rubella (MMR) vaccine, including an early dose for infants 6–11 months, according toCDC’s measles vaccination recommendations for international travel.

+4 more

Source: CDC Travelers' Health

View Complete Health Guide

Is September a Good Time to Visit Seoul?

👍Recommended for planning your trip(65/100)

Short Answer

Seoul's September delivers on its reputation: 25°C, 24% rain, 8.1h sunshine. The trade-off? Peak crowds and prices at 92% capacity.

Decision Factors

Vaccinations required

Yellow Fever

Peak tourist season

92% of annual peak - expect crowds and peak prices

Ideal temperature range

25.2°C - perfect for sightseeing and outdoor activities

Health precautions needed

Be aware of: Leptospirosis, Avian/Bird Flu, Hantavirus

Plenty of sunshine

8.1h of sunshine daily

Rich cultural heritage

4 UNESCO World Heritage sites nearby

Good For

🥾
Outdoor enthusiasts
Ideal hiking conditions: 25.2°C, 24% rain chance
🏛️
Cultural tourists
Comfortable conditions for exploring museums and sites
💑
Honeymoon couples
Wedding score 96/100 with romantic weather conditions
💼
Business travelers
Climate-controlled meetings unaffected by weather

Who Should Avoid

💰
Budget travelers
Peak season means premium prices everywhere
👴
Elderly travelers
78% humidity creates difficult conditions

"According to 30YearWeather's analysis of 30 years of NASA POWER satellite data,Seoul in September averages 25°C with 24% precipitation probability."

📊 Source: 30YearWeather.com🛰️ Data: NASA POWER (1991-2021)View Methodology →

Frequently Asked Questions: Seoul in September

What are the temperatures in Seoul in September?

Daytime highs average 25°C, nights drop to 17°C. Temperatures remain fairly consistent.

How many rainy days in Seoul in September?

Expect around 14 days with measurable rainfall. Rain is unlikely to disrupt plans.

What to wear in Seoul in September?

Comfortable casual wear with a light jacket for evenings.

Is September peak season in Seoul?

This is typically peak season with higher prices. Book 2-3 months ahead.

Seoul Weather in September

Seoul September Weather Calendar