January weather forecast
Jeju, South Korea

The transition from winter to spring in Jeju, South Korea, starts with January, best known for its chilly temperatures with highs of 8.3°C (46.9°F) and lows dipping to 3.2°C (37.8°F). The month is considered cold, yet precipitation is relatively moderate in the form of scattered showers and possibly snow, keeping the island's vegetation lush. January's cooler climate also offers the perfect ambience for indoor activities or venturing into the island's hot springs. This month also marks an offseason making it an appealing time for those seeking a more tranquil and less crowded experience in Jeju. Despite the cold, January still calls for commendable outdoor adventures such as climbing Hallasan, the island's towering volcanic peak.

Temperature

January brings the lowest temperatures in Jeju, with an average high of 8.3°C (46.9°F) and an average low of 3.2°C (37.8°F).

Humidity

In Jeju, the average relative humidity in January is 65.3%.

Rainfall

In January, in Jeju, the rain falls for 12.6 days. Throughout January, 65mm (2.56") of precipitation is accumulated. Throughout the year, in Jeju, South Korea, there are 130.2 rainfall days, and 1498mm (58.98") of precipitation is accumulated.

Sea temperature

In Jeju, South Korea, the average seawater temperature in January is 14.8°C (58.6°F).
Note: Swimming at temperatures less than 10°C (50°F) in 14.8°C (58.6°F) is feasible with the right swimsuit; if not, expect cold shock and breathlessness. A quick swim at 13°C (55.4°F) without adequate warmth can be discomforting.

Daylight

In January, the average length of the day is 10h and 13min.
On the first day of the month, sunrise is at 07:37 and sunset at 17:36. On the last day of January, in Jeju, sunrise is at 07:31 and sunset at 18:03 KST.

Sunshine

The month with the least sunshine is January, with an average of 2.3h of sunshine.

UV index

January and December, with an average maximum UV index of 3, are months with the lowest UV index in Jeju. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the average person.
Note: In January, the maximum UV index of 3 suggests this advice:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. To avoid the Sun's strongest rays, limit exposure around the mid-day period. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.