Jeju Weather in August
🇰🇷 South Korea
Asia › 🇰🇷 South Korea › Jeju
Updated: March 2026
Is August a Good Time to Visit Jeju?
August is a fair time to visit Jeju (5/10). With 10 daily sunshine hours and only 17 rain days, this month delivers genuinely reliable outdoor conditions, ranking it the sunniest month of the year in Jeju. Culture-focused travellers and those who prefer lighter crowds will find August a practical choice, with prices running lower than peak August without sacrificing all the good weather. September offers a similar profile at lower hotel rates if dates are flexible. Watch out for prolonged rain stretches: with 17 wet days, a fully outdoor itinerary is risky. Build in museum days and covered market visits as contingency. Planning tips: accommodation is generally available without long lead times, and flight prices are typically lower than peak season. Flexible travellers will find the best deals by booking 2-4 weeks ahead. Mid-week arrivals consistently unlock lower hotel rates than weekend check-ins.
Jeju in August rewards travelers with average highs of 28°C and overnight lows around 25°C. Expect around 17 rainy days, so a compact umbrella is worth carrying. With 10 daily sunshine hours on average, conditions are warm and inviting for outdoor exploration.
28°C
Avg High
25°C
Avg Low
17 days
Rain Days
10h
Sunshine
70%
Humidity
Temperature in Jeju in August
The narrow 3°C gap between daytime and overnight temperatures, characteristic of coastal cities with maritime moderation, means a single mid-layer works across the whole day. Humidity averages 70%, which is comfortable for most visitors. On warmer days, lighter fabrics help with the mild stickiness in the afternoon. UV index averages 9 this month, classed as high to very high. SPF 30+ sunscreen, a brim hat, and sunglasses are not optional between 10am and 4pm. Wind averages 17 km/h, light enough to be refreshing on warm days but noticeable in open coastal areas or elevated viewpoints. In Fahrenheit: 82°F average high, 77°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).
Temperature in August
Monthly Precipitation (mm)
What to Wear in Jeju in August
Packing for Jeju in August means dressing for 28°C days and 25°C evenings. A light cotton tee with a casual overshirt works well at 28°C, the overshirt doubles as a layer for air-conditioned venues. Evening temperatures settle at 25°C, a modest 3°C drop that a light cardigan or denim jacket covers. Comfortable walking trainers are the versatile choice for both outdoor sightseeing and indoor venues. With 17 rain days expected, a compact travel umbrella is worth the bag space. A waterproof jacket is better than an umbrella if you plan full-day outdoor routes. For temple and religious site visits, carry a lightweight scarf or sarong to cover shoulders and knees, required at most major sites across the region.
Local tip: Temple and religious site visits require covered shoulders and knees in most of Jeju's heritage areas. A lightweight scarf or sarong weighs almost nothing and solves the problem instantly.
Events in Jeju in August
August has no major festivals or public holidays in Jeju, which is one of its practical advantages for independent travellers. Attractions run at lower capacity than during peak event periods, queues are shorter, and accommodation is easier to find without needing to book many months in advance. Local restaurants, markets, and transport operate at a relaxed pace, making this an ideal time for visitors who prefer a more authentic, unhurried experience of everyday city life rather than large crowds drawn in by a single major headline event.
What to Pack for Jeju in August
Based on 28°C average highs and 17 rainy days
- Light layers for morning and evening
- Breathable T-shirts and comfortable trousers
- UV-protective sunglasses
- Quick-dry travel towel
- Anti-chafe balm for long walking days
- Moisture-wicking synthetic fabrics for active days
- Compact folding umbrella
- Waterproof outer layer or packable rain jacket
- Quick-dry clothing that recovers fast after a shower
- SPF 30+ sunscreen
- Comfortable walking shoes (a second pair lets the first air out overnight)
- Universal travel adapter
- Small day pack for city exploration
- Reusable water bottle
Best Activities in Jeju in August
- Explore outdoor markets and street food stallsMid-morning (10am-12pm)At 28°C, the temperature is ideal for extended walking without overheating
- Guided walking tour of the historic centreMorning or late afternoonComfortable temperatures allow several hours on foot without fatigue
- Visit rooftop viewpoints and observation decksGolden hour (1 hour before sunset)Warm clear evenings provide exceptional visibility for panoramic photography
- Day trip to the surrounding countryside or coastFull day (depart by 8am)August is reliably dry enough for rural day trips without weather risk
- Spend a morning in the national or city art museumOpens at 10am; arrive earlyWith 17 rain days expected, having a full-day indoor plan is practical insurance
- Cooking class focused on regional cuisineHalf-day sessions run 10am-1pm or 3-6pmIndoor activity that fills a rainy half-day with genuine cultural content
- Visit covered historical sites: cathedral, palace, or bazaarAny time; most crowded middayRoofed monuments and covered markets provide exploration without weather exposure
- Visit the main botanical garden or city park at seasonal peakYear-round; best light in morningAugust brings distinct seasonal changes to public green spaces worth exploring
- Seek out chilled local specialities: cold-brew tea, ice desserts, or chilled seafood at street-level stallsAny time; most atmospheric in evening marketsHot-weather street food culture peaks in August, with vendors setting up specifically for warm evenings
Why is Jeju warm in August?
Jeju's August heat is driven by the Asian summer monsoon system, as the low-pressure cell that forms over the heated landmass draws warm, humid air from the oceans. The result is temperatures averaging 28°C with high moisture in the air. Overnight temperatures remain elevated at 25°C, as clouds and humidity prevent the earth from radiating heat away after sunset. Climate data: Open-Meteo ERA5 (1991–2020).
Sunshine Hours
The average number of hours per day with direct sunlight. Calculated from satellite measurements. Days with more than 7 hours of sunshine are ideal for outdoor activities. Under 3 hours means overcast conditions dominate.
UV Index
A scale from 0-11+ measuring ultraviolet radiation intensity. UV 0-2: Minimal risk. UV 3-5: Moderate -- wear sunscreen. UV 6-7: High -- hat and SPF 30+ essential. UV 8-10: Very High -- limit midday exposure. UV 11+: Extreme -- seek shade between 10am-4pm.
Rain Days
A rain day is counted when precipitation exceeds 0.1mm. This threshold captures even light drizzle. Unlike total rainfall in mm, rain days tells you how often you might need an umbrella, which is useful for planning outdoor activities.
Humidity
Relative humidity as a percentage. Below 40%: Dry -- skin and throat may feel parched. 40-60%: Comfortable -- ideal for most people. 60-80%: Sticky -- light, breathable fabrics recommended. Above 80%: Muggy -- heat feels more intense; quick-dry clothing is essential.
Frequently Asked Questions: Jeju in August
August ranks 1st sunniest of the year in Jeju, with an average 10 daily sunshine hours. The driest months are October, February, and November. August is the hottest month (28°C avg high); January is the coolest (7°C). From here, temperatures fall 3°C into September. Compared to last month (July: 27°C high, 16 rain days), August is warmer and wetter. August is among the top three sunniest months to visit Jeju.
Year-Round Climate
Plan Your Trip to Jeju
Nearby Destinations with Similar Weather
These cities are within 500 km and experience broadly comparable weather conditions during the same calendar month, making them practical standalone alternatives or worthwhile additions to a longer regional itinerary.
Data Sources for Jeju
Climate normals represent 30-year averages (1991-2020). Individual years may vary.