Monthly weather averages & travel planning

Asia › 🇰🇷 South Korea › Jeju
Updated: March 2026
January is a avoid time to visit Jeju (2/10). Average highs of 7°C and 5 sunshine hours daily make conditions workable, though not exceptional. January suits travellers visiting for indoor culture, food, and architecture rather than outdoor activities. Pack accordingly for 9 potential rain days. February offers a similar profile at lower hotel rates if dates are flexible. The 7°C highs require proper cold-weather clothing; many visitors underestimate how far the wind chill drops the perceived temperature, particularly near water or at elevated viewpoints. Planning tips: most accommodation categories have availability, and last-minute deals are common. The quieter streets and shorter queues can make this a genuinely enjoyable time to visit for the right type of traveller. Budget-conscious visitors will find the best value of the year in this period.
Jeju in January rewards travelers with average highs of 7°C and overnight lows around 4°C. Expect around 9 rainy days, so a compact umbrella is worth carrying. With 5 daily sunshine hours on average, conditions are cool and bracing, well suited for active days on foot.
7°C
45°F
Avg High
4°C
39°F
Avg Low
9 days
62 mm total
Rain Days
5h
per day avg
Sunshine
70%
Moderate
Humidity
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. The UV index of 2 is low, meaning sun exposure is minimal concern and sunscreen is largely optional. Wind averages 22 km/h, light enough to be refreshing on warm days but noticeable in open coastal areas or elevated viewpoints. In Fahrenheit: 45°F average high, 39°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).
Packing for Jeju in January means dressing for 7°C days and 4°C evenings. Layering is key: a thermal base, mid-layer fleece, and a windproof outer jacket for 7°C highs that feel colder in the wind. Evening temperatures settle at 4°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. A compact foldable umbrella weighs almost nothing and earns its keep across 9 potential rainy days.
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.
January 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.
Based on 7°C average highs and 9 rainy days
January in Jeju reflects a mid-latitude climate pattern, with temperatures averaging 7°C by day and 4°C overnight. The city sits at 33 degrees north latitude, where the balance between solar radiation and heat loss drives conditions that are neither extreme nor static. Cold conditions reflect the dominance of polar or continental air masses, which bring dry, stable weather with low humidity. Day-to-night temperature variation of 3°C is small, typical of maritime-influenced climates. 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.
Jeju in January
January ranks 12th sunniest of the year in Jeju, with an average 5 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 rise 1°C into February. Compared to last month (December: 10°C high, 8 rain days), January is cooler and wetter. January is one of the least sunny months, but that often means lower prices and fewer fellow tourists.
| Month | High | Low | Rain Days | Sun | Details |
|---|---|---|---|---|---|
| January | 7°C | 4°C | 9 | 5h | View |
| February | 8°C | 4°C | 8 | 7h | View |
| March | 11°C | 7°C | 10 | 8h | View |
| April | 16°C | 11°C | 9 | 9h | View |
| May | 20°C | 15°C | 10 | 9h | View |
| June | 23°C | 19°C | 13 | 8h | View |
| July | 27°C | 24°C | 16 | 9h | View |
| August | 28°C | 25°C | 17 | 10h | View |
| September | 25°C | 22°C | 13 | 8h | View |
| October | 20°C | 17°C | 7 | 9h | View |
| November | 15°C | 11°C | 8 | 7h | View |
| December | 10°C | 6°C | 8 | 6h | View |
January
9 rain days, 5h sun
February
8 rain days, 7h sun
March
10 rain days, 8h sun
April
9 rain days, 9h sun
May
10 rain days, 9h sun
June
13 rain days, 8h sun
July
16 rain days, 9h sun
August
17 rain days, 10h sun
September
13 rain days, 8h sun
October
7 rain days, 9h sun
November
8 rain days, 7h sun
December
8 rain days, 6h sun
Cities within 500 km with comparable weather conditions
Data Sources for Jeju
Climate normals represent 30-year averages (1991-2020). Individual years may vary.