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 is the month that records the lowest temperatures, with averages ranging from a high of 8.3°C (46.9°F) to a low of 3.2°C (37.8°F).

Humidity

In January, the average relative humidity is 65.3%.

Rainfall

In January, the rain falls for 12.6 days. Throughout January, 65mm (2.56") of precipitation is accumulated. In Jeju, during the entire year, the rain falls for 130.2 days and collects up to 1498mm (58.98") of precipitation.

Sea temperature

In Jeju, in January, the average water temperature is 14.8°C (58.6°F).
Note: If planning to swim in 14.8°C (58.6°F) under 10°C (50°F), wear a protective suit. Neglecting this advice might cause immediate cold shock and troubled breathing. A splash around 13°C (55.4°F) is not much warmer.

Daylight

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

The months with the lowest UV index are January and December, with an average maximum UV index of 3. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.
Note: In January, a daily maximum UV index of 3 leads to the following instructions:
Take precautions - Protection against sun damage is advised. Minimize direct exposure to the Sun during midday when its radiation is at its peak. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.