2026 Climate Averages

Weather: Jeju Island — September

The weather is near-perfect with ideal temperatures and minimal rain. Recommended month to visit.

🌟 Climate Overview

September is an excellent time to visit Jeju Island. Warm weather with highs of 28°C—great for outdoor activities. This is one of the wettest months—waterproof gear is essential. As peak season, expect higher prices and more tourists. Sea temperature of 29°C is perfect for swimming.

5.2
GoTripzi Score Fair

Based on weather comfort, crowds, prices, and activity options

Avg High

28°C

Avg Low

24°C

Rainy days

17days

Daylight

12.4h

Feels like 31°C / 26°C — humidity makes it feel warmer

Rainfall

275mm

Sunshine

7.9h/day

Humidity

81%

Very Humid
Sun Strength

5.6

High
Wind

18 km/h (gusts 40)

Sea Temp

29°C 🏊 Comfortable

Is September a good time to visit Jeju Island?

The weather is near-perfect with ideal temperatures and minimal rain.

Now

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Feels like --
Wind --
Humidity --
UV Index --
Local time

Air Quality

Travel Context

  • Crowds
    Very Busy
  • Travel Costs Shoulder Rates

Daylight

Sunrise

06:18

Sunset

18:43

12.4h daylight

Visiting Jeju Island in September: Pros & Cons

Pros

  • Comfortable temperatures for sightseeing
  • Warm sea perfect for swimming and snorkeling
  • One of the best months to visit

Cons

  • Frequent rain may disrupt outdoor activities
  • Peak season — expect crowds and higher prices

Things to Do in September

Events & Festivals

🎊
Chuseok
September/October Holiday

Recommended for This Weather

🏊 Swimming & beach activities
🤿 Snorkeling & water sports
🏖️ Beach relaxation & sunbathing
🏛️ Museums & galleries
🍳 Cooking classes & food tours
🎭 Cultural tours & local experiences

Jeju Island Weather by Month

Month Avg High Avg Low Rain Sunshine Humidity UV Index Crowds Condition
Jan 10°C 5°C 9d (59mm) 5.7h
70% Humid
3.3 Moderate
Good
Feb 10°C 6°C 9d (79mm) 6.3h
71% Humid
4.4 Moderate
Good
Mar 14°C 9°C 10d (98mm) 7.6h
72% Humid
6.2 High
Good
Apr 18°C 12°C 8d (93mm) 8.9h
72% Humid
7.8 Very High
Excellent
May 21°C 16°C 9d (129mm) 9.2h
77% Humid
8.2 Very High
Excellent
Jun 25°C 21°C 13d (213mm) 8h
85% Very Humid
7.2 Very High
Wet
Jul 29°C 25°C 18d (254mm) 8.4h
87% Very Muggy
6.8 High
Wet
Aug 30°C 26°C 19d (177mm) 9.9h
83% Very Muggy
7.1 Very High
Wet
Sep Current 28°C 24°C 17d (275mm) 7.9h
81% Very Humid
5.6 High
Excellent
Oct 22°C 18°C 7d (48mm) 8.2h
72% Humid
5.2 High
Excellent
Nov 17°C 13°C 7d (97mm) 6.9h
70% Humid
3.9 Moderate
Good
Dec 11°C 7°C 7d (31mm) 5.8h
68% Humid
3 Moderate
Good

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5
3
3
Your Best MonthJunScore: 8.5

Where to Stay

See hotels, apartments & rentals around Jeju Island – live prices from Booking.com, Expedia, Vrbo and more

Jeju Island

Volcanic island, including waterfalls, Hallasan Mountain hike and Seongsan Sunrise Peak, lava tubes, beaches, and Hallasan crater.

View Full Destination Guide

What to Pack for September

Summer clothing like shorts, t-shirts, and sundresses will be comfortable. Bring a light cardigan for air-conditioned spaces. A waterproof jacket and shoes are non-negotiable — showers are frequent.

Warm Very Busy

🎒Personalized Packing List

Tell us about your trip and we'll create a custom packing list based on the weather.

Your Packing List

📋Essentials
👕Clothing
👟Footwear
🎒Accessories
🧴Toiletries & Health

Planning a trip to Jeju Island?

🔥 Peak season — book early for best rates

Frequently Asked Questions

Is September a good time to visit Jeju Island?
September is typically excellent for visiting Jeju Island, with average highs of 28°C and around 17 rainy days. Plan your activities accordingly—outdoor sightseeing is best on dry days, while rainy days are perfect for museums and indoor attractions.
Does it get cold at night in Jeju Island in September?
Nights stay pleasantly warm in Jeju Island during September, around 24°C. Light evening wear is sufficient, and outdoor dining is very comfortable. Many locals and visitors enjoy late-night walks and outdoor activities after sunset.
What should I pack for Jeju Island in September?
With highs of 28°C and lows of 24°C in September, we recommend: Compact umbrella, Waterproof jacket/shell, Water-resistant shoes, Lightweight breathable clothes. Layering is key as temperatures can vary between air-conditioned interiors and outdoors. Comfortable walking shoes are essential for cobblestone streets.
Does it rain a lot in Jeju Island in September?
Jeju Island typically sees around 17 rainy days in September. Rain is usually in the form of brief showers rather than all-day downpours, so a compact umbrella is sufficient. Mornings tend to be drier, making them ideal for outdoor sightseeing.
Can you swim in Jeju Island in September?
Yes, September is excellent for swimming in Jeju Island! With warm air temperatures around 28°C, the water is comfortable for extended beach sessions. This is peak beach season, so arrive early to secure a good spot at popular beaches.
How many hours of daylight are there in Jeju Island in September?
In September, Jeju Island gets approximately 12.4 hours of daylight per day. This affects how much sightseeing you can fit in—longer days mean more time for outdoor activities, while shorter days are perfect for cozy museum visits and early dinners.
Is September peak season in Jeju Island?
Yes, September is peak season in Jeju Island. Expect higher prices for accommodation and more crowds at popular attractions, but also the best weather conditions. Book hotels and major attractions in advance to secure availability and better rates.

Weather Data: Based on 2020–2025 historical climate data from Open-Meteo

Solar calculations: SunCalc (timezone: Asia/Seoul)

Last Updated: February 2026