Jeju-do Climate

Last updated: January 18, 2025

Jeju-do, South Korea, experiences a Cfa climate classification, characterized by humid subtropical conditions. The island's temperatures oscillate notably throughout the year, with a minimum of -3°C (27°F) recorded in January, rising to an average of 16°C (61°F) annually. The warmest months peak at 32°C (91°F) in August, illustrating the region's significant seasonal temperature variation. These climatic conditions contribute to Jeju's lush landscapes and biodiversity, making it a unique ecological hotspot.

Jeju-do temperature by month

In Jeju-do, South Korea, temperature patterns exhibit distinct seasonal trends, transitioning from the cold winter months to a warm, humid summer. January and February are the coldest months, with minimum temperatures dipping to around -3°C (27°F) and -2°C (29°F), respectively, accompanied by average highs reaching only 19°C (66°F) in January. As spring approaches in March and April, temperatures gradually rise, with average conditions shifting from 10°C (51°F) to 13°C (57°F), seeing maximums soar to 22°C (71°F) in April. The onset of summer in May ushers in milder conditions, peaking at 25°C (78°F) as minimums stabilize around 10°C (49°F). July and August present the warmest period, marked by highs of 32°C (91°F), while September begins a gradual cooling phase. By October and November, temperatures retract to more moderate levels, with averages around 19°C (66°F) and minimums above 6°C (43°F). The cycle concludes in December, where temperatures begin to dip again, reflecting the island's dynamic seasonal climate.

Monthly Temperatures in Jeju-do, South Korea

The chart illustrates Jeju-do's temperature patterns throughout the year, with values aggregated from various locations across the region. It highlights seasonal variations and temperature changes across the months.
JanFebMarAprMayJunJulAugSepOctNovDec444451566370778174665748
Data source: Jeju-do temperature data aggregated from multiple regional locations, generated using Copernicus Climate Change Service information.
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The average of daily temperatures (24 hours) calculated across all days in the month.

Seogwipo experiences a minimum temperature of -3°C (27°F) in January, rising to a maximum of 32°C (91°F) in August, as detailed in the monthly temperatures in Seogwipo. In comparison, Jeju City has a slightly warmer minimum of -2°C (29°F) in January and a maximum of 31°C (88°F) in August, according to the monthly temperatures in Jeju City.

Precipitation Patterns in Jeju-do

Jeju-do, South Korea, experiences a varied precipitation pattern throughout the year, heavily influenced by its humid subtropical climate. The winter months of January and February receive relatively low rainfall, with 55 mm (2.2 in) and 59 mm (2.3 in) respectively, spreading over 9 days. As spring approaches, March and April see a notable increase, averaging 103 mm (4.1 in) and 95 mm (3.7 in) respectively, with the number of wet days remaining manageable. A continuation of this trend occurs in May, where precipitation hits 103 mm (4.1 in), signaling the transition toward the wetter summer months.

The summer season brings significantly higher rainfall, particularly in June, July, and August, with totals exceeding 150 mm (5.9 in) and peaking at 226 mm (8.9 in) in August—often the wettest month. September follows suit with even higher totals of 296 mm (11.6 in) as the monsoon season culminates. This period is characterized by more frequent rain, with up to 16 days of precipitation in August. The fall months of October and November see a decline in rainfall, with totals dropping to 110 mm (4.3 in) and 44 mm (1.7 in), respectively, while December experiences a slight increase again to 60 mm (2.4 in), ensuring a rich ecological environment year-round.

Monthly Average Precipitation in Jeju-do, South Korea

The average monthly precipitation in Jeju-do, providing insights into seasonal rainfall patterns and the region's precipitation trends throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec5559103951031501852262961104460
Data source: Jeju-do precipitation data aggregated from multiple regional locations, generated using Copernicus Climate Change Service information.
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Sunshine Duration in Jeju-do

In Jeju-do, South Korea, sunshine duration exhibits a remarkable seasonal trend, showcasing the island’s transition from winter’s overcast days to the bright, sun-drenched months of summer. January begins the year with a modest 161 hours of sunshine, gradually increasing to 226 hours in February, signaling a shift towards more favorable weather. As spring arrives, the hours of sunlight continue to rise significantly, peaking in May at 302 hours. This steady climb reaches its zenith in the summer months, particularly in August, which basks in an impressive 316 hours of sunshine, offering the longest and sunniest days of the year.

As the summer wanes, sunshine hours begin to decline; yet, the decline remains gradual, with September still enjoying 264 hours of sunlight. The fall season sees further reduction, with October and November capturing 267 hours and 228 hours, respectively, culminating in December's 198 hours. This seasonal pattern highlights the island’s broad appeal for visitors seeking sun during the warmer months while revealing the softer, yet still pleasant, offerings of the cooler seasons. Overall, Jeju-do serves as a vibrant climatic showcase, where sunshine plays a pivotal role in shaping local ecosystems and enhancing recreational opportunities throughout the year.

Monthly Sunshine in Jeju-do, South Korea

Monthly sunshine duration represents the total hours of direct sunlight Jeju-do receives each month, excluding periods when the sun is obscured by clouds or other obstructions.
JanFebMarAprMayJunJulAugSepOctNovDec161h226h265h290h302h295h296h316h264h267h228h198h
Data source: Jeju-do sunshine duration data aggregated from multiple regional locations, generated using Copernicus Climate Change Service information.

Jeju-do UV Index Trends

The UV Index in Jeju-do, South Korea, demonstrates significant variations across the seasons, reflecting the intensity of solar radiation throughout the year. During the winter months, particularly January and December, the UV Index is relatively low at 4, categorized as moderate, with recommended sunburn exposure times of 30 minutes. However, as February arrives, the index climbs to 6 (high), indicating a shift toward increased UV radiation. This trend accelerates dramatically in spring, with March and April witnessing UV Index values of 8 and 10 (both rated as very high), while May retains a peak of 10, highlighting the necessity for sun protection.

Summer ushers in the highest UV Index levels, reaching an extreme rating of 11 in June and a peak of 12 during July and August, where the burn time shrinks to just 10 minutes. As autumn arrives, a slow decline is observed, with September dropping back to 10 and further decreasing to 7 in October, categorized as high, and 6 in November. This marked seasonal fluctuation serves as a crucial reminder for residents and visitors alike in Jeju-do to adjust their sun protection measures accordingly, especially during the intensely sunny summer months when UV exposure poses a significant health risk.

Monthly Maximum UV Index for Jeju-do, South Korea

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Jeju-do. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec468101011121210764
Data source: Jeju-do UV Index data aggregated from multiple regional locations, generated using Copernicus Climate Change Service information.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

Daylight Hours in Jeju-do

In Jeju-do, South Korea, daylight duration exhibits distinct variability throughout the year, characterized by gradual changes that reflect the shifting seasons. During the winter months, January and February offer a consistent 10 hours of daylight. As spring commences in March, daylight increases to 11 hours, paving the way for longer days ahead. Notably, April and May see daylight peaking at 13 hours, providing ample opportunity for outdoor activities and enjoyment of the island's natural beauty.

The summer months of June and July maximize daylight availability, with each month boasting 14 hours, creating ideal conditions for exploration and recreational pursuits. As August rolls in, daylight begins to taper off slightly to 13 hours before the transition to fall. September sees a reduction to 12 hours, while October and November continue this trend, dropping to 11 hours and 10 hours, respectively. By December, daylight decreases further to 9 hours, marking the onset of winter. This cyclic pattern of daylight duration significantly influences the island's climate and local lifestyle, guiding activities and cultural practices throughout the year.

Average Monthly Daylight Hours in Jeju-do, South Korea

This chart shows the total daylight hours Jeju-do receives each month, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec611h658h718h780h832h858h845h799h740h679h625h597h
Data source: Jeju-do daylight hours, calculated based on aggregated data for various regional locations, determined by the times between sunrise and sunset.

Climate Highlights of Jeju-do's Popular Destinations

Gaigeturi, South Korea experiences a diverse climate throughout the year, characterized by warm summers and chilly winters. January’s temperatures range from -1°C to 18°C, with significant snowfall, while summer months like July and August see highs reaching 30°C. Precipitation peaks in September, accumulating 265 mm, making it the wettest month. Sunshine is abundant, particularly in August, with 318 hours of sunlight, promoting a vibrant natural landscape. For more details, visit Gaigeturi climate.

Jeju City experiences a temperate climate with distinct seasonal changes. Winter months (January to March) can be chilly, with temperatures ranging from -2°C to 10°C (29°F to 51°F), and moderate rainfall averaging around 50-100 mm. Summers (June to August) are warm and humid, with temperatures soaring between 21°C to 31°C (70°F to 88°F) and precipitation peaking in September at 298 mm (11.7 in). Sunshine is abundant, especially in summer, where August sees up to 318 hours of sunlight. For more detailed information, visit Jeju City climate.

Seogwipo, South Korea, experiences a temperate climate with notable seasonal variations in temperature and precipitation. Winter months like January and February see minimum temperatures around -3°C (27°F) and average highs of 6°C (43°F), while summers, particularly July and August, boast warm averages of 25°C (78°F) and 27°C (81°F), respectively. Rainfall peaks during late summer and early fall, with September receiving up to 325 mm (12.8 in) of precipitation, while the sunniest months are from May to August, offering over 290 hours of sunshine. For more details, visit Seogwipo climate.

Conclusion

In conclusion, Jeju-do, South Korea, presents a dynamic climate characterized by notable variations in temperature, precipitation, sunshine duration, UV index, and daylight throughout the year. From the cold winters with limited daylight and moderate UV levels to the warm summers marked by extended sunshine and extreme UV exposure, the island's climate fosters a rich and diverse ecosystem, as well as a vibrant cultural landscape. Understanding these climatic trends is essential for both residents and visitors, as it allows for better preparation and adaptation to the island's seasonal rhythms. Ultimately, Jeju-do's unique climate not only enhances its natural beauty but also influences the lifestyle and activities of those who call it home or come to explore its offerings.

Discover the Climate of Jeju-do's Places

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