Weather in Jeju City

Planning a trip to Jeju City? This section will help you stay updated with the most current weather information. Here you will find fresh data, detailed forecasts, and visual charts.

The climate in Jeju City, located in South Korea, can be described as temperate marine, with four clearly defined seasons. The city experiences noticeable temperature fluctuations throughout the year, allowing tourists to enjoy a variety of weather conditions depending on the time of their trip.

Winters (December-February) in Jeju City are relatively mild, with an average temperature of around 6°C - 7.5°C. Summer (June-August) is warm and humid, with average temperatures varying from 20.7°C in June to 26.6°C in August. The summer months, especially July and August, along with September, are characterised by the highest number of rainy days (up to 15 days per month). At the same time, September also stands out as the month with the highest volume of rainfall (8 mm).

Spring (March-May) and autumn (October-November) are transitional seasons with comfortable temperatures. In spring, the temperature gradually rises from 10.1°C in March to 16.7°C in May. In autumn (October-November), the weather is also pleasantly comfortable: the temperature smoothly decreases from approximately 18.3°C in October to 13.2°C in November. These shoulder seasons are often considered the most pleasant for visiting Jeju City thanks to moderate weather and fewer rainy days compared to the wetter summer season and winter.

The temperature regime in Jeju City demonstrates a clear change of seasons with a noticeable annual range. The hottest month is August, when the average temperature reaches 26.6°C. During this period, daytime highs confidently hold around 27.9°C, and nights remain very warm, with a minimum temperature of about 25.4°C. On the other hand, January is the coldest month of the year. The average temperature in January is 6.0°C, while night-time lows drop on average to 4.4°C, and daytime highs rarely exceed 7.6°C.

The summer period, from June to August, is characterised by increasing heat. In June, the average temperature is a comfortable 20.7°C (minimum 19.3°C, maximum 22.2°C), gradually rising in July to 25.1°C (minimum 23.9°C, maximum 26.3°C) and reaching its peak in August. A characteristic feature of the summer months is the relatively small difference between day and night temperatures, usually not exceeding 2-3°C. This creates a sensation of constantly warm, and at the peak of the season – hot weather, often accompanied by high humidity, which is typical for the city's island location.

Winter in Jeju City, covering December, January, and February, is distinguished by cool but generally mild weather. Monthly average temperatures fluctuate from 6.0°C in January to 7.5°C in December. Night-time temperatures in the coldest period (January-February) drop to 4.4°C - 5.1°C, and daytime temperatures rise to 7.6°C - 9.1°C. Diurnal temperature fluctuations in winter are slightly more noticeable than in summer, averaging 3-4°C, but extreme drops are usually not observed, and the weather remains above the freezing point.

In Jeju City, precipitation is observed throughout the year, however, its intensity and frequency vary noticeably depending on the season. One can distinguish a wetter summer-autumn period and relatively drier winter and spring months in terms of precipitation volume. The city does not have a clearly defined absolutely dry season, but the difference in the amount of precipitation and rainy days between months is significant.

The greatest amount of precipitation and rainy days occurs in the summer months and early autumn. The period from June to September is characterised by the highest frequency of rain. In particular, July, August, and September are the months with the greatest number of rainy days – each averages 15 such days. In terms of total precipitation volume, September leads, with 8 mm falling. In June and July, the amount of precipitation is 6 mm, and in August – 5 mm. During the summer months and early autumn, it rains often, however, the total amount of falling precipitation remains small, which indicates the predominantly light, possibly drizzling, character of these frequent rains.

In the remaining months of the year, from October to May, the total amount of precipitation is noticeably lower. The "driest" months in terms of moisture volume are January and December, when only 2 mm of precipitation is recorded each. However, in terms of rain frequency, the winter months (December – 12 days, January – 10 days, February – 11 days) turn out to be quite wet regarding the number of days with precipitation, surpassing some spring and autumn months. For example, in April, May, and October, there are on average only 8 rainy days, and in March and November 9 days each, making them the "driest" in terms of precipitation frequency among all months. Considering that average temperatures even in winter remain above zero, precipitation in Jeju City falls predominantly in the form of rain.

When planning a trip to Jeju City, it is important to choose your wardrobe correctly to feel comfortable in any weather. The key principle is layering, as the temperature can change throughout the day. Always take comfortable walking shoes with you, as the island is perfect for long walks. An umbrella or a light raincoat will be an indispensable accessory, especially if your trip falls during the period from June to September, when the number of rainy days reaches its maximum.

In winter (December-February), when the average temperature hovers around 6-7.5°C, you will need warm clothes: sweaters, a fleece jacket, an insulated jacket (preferably wind- and waterproof), a hat, gloves, and a scarf. In spring (March-May) and autumn (October-November), the weather is milder, with average temperatures from 10°C to 18°C. At this time, light jackets, cardigans, jeans or heavy trousers, as well as t-shirts and long-sleeved shirts for creating layered looks are relevant. Do not forget an umbrella, as rains are possible, especially in September, which is the rainiest month by precipitation volume.

Summer (June-August) in Jeju City is warm and humid, with average temperatures rising to 20-27°C. Choose light, breathable clothing made from natural fabrics: t-shirts, shorts, sundresses. Given the large number of rainy days (12-15 per month), a compact umbrella or a light waterproof windbreaker will be very useful. Also, be sure to take sunscreen, a hat, and sunglasses for protection against ultraviolet radiation, especially on clear days between rains.