Jeju Island Sea Temperature

Updated Mon 05:53 (Asia/Seoul)

South Korea · Forecast updated Aug 10, 2026, 05:53 UTC

Current Sea Temperature

28.3°C

82.9°F

Very warm water

Versus this month's average

0.8°C below

The August average in our archive is 29.1°C (84.4°F).

Recent trend

Warming by 0.5°C

Seven-day average: 29.6°C, versus 29.1°C in the prior seven days.

What to wear

Very warm water

Swimwear is usually enough; a rash guard adds sun protection.

Cold tolerance varies. Wind, session length, sunshine, and exertion also affect comfort; temperature alone does not describe sea conditions.

Sea Surface Temperature Over the Year

In the data collected for Jeju Island, monthly averages range from about 23.0°C (73.4°F) in June to 29.1°C (84.4°F) in August.

Over the past 30 days, the average sea temperature in Jeju Island has been 28.3°C.

Month	Min	Average	Max
June	22.2°C / 72.0°F	23.0°C / 73.4°F	24.6°C / 76.3°F
July	23.4°C / 74.1°F	26.7°C / 80.0°F	30.9°C / 87.6°F
August	28.0°C / 82.4°F	29.1°C / 84.4°F	30.3°C / 86.5°F

Profile calculated from 1694 hourly forecast records across 3 monthly periods. This is a growing archive, not a long-term climate normal.

Volcanic island with clear coves, lava arches and the famous haenyeo divers.

The current sea surface temperature in Jeju Island is 28.3°C. Over the last 30 days, the average has been 28.3°C.

The warmest monthly average in the Jeju Island archive is August, at around 29.1°C (84.4°F).

The coldest monthly average in the archive is June, at around 23.0°C (73.4°F).

At 28.3°C, the water is usually comfortable for swimming and snorkeling.

See how today's sea temperature, wave height, wind, and tides combine into a detailed snorkeling score for Jeju Island.