Measurements:
°C
°F
Jeju
78°F
NE 8 mph
Feels like: 82°F
Precip: 75%
World Resorts South Korea Jeju Weather

Jeju Sea Water Temperature

Current Sea Water Temperature:
+76.2°F
Maximum Sea Water Temperature in July: 87.8°F
Minimum Sea Water Temperature in July: 70.6°F
Average water temperature in July: 79.5°F

Sea Water Temperature for the Last 10 Days:

July 04 76.2°F June 29 75.4°F
July 03 75.4°F June 28 74.2°F
July 02 74.6°F June 27 74.2°F
July 01 75.0°F June 26 73.0°F
June 30 75.6°F June 25 73.4°F

When is the Warmest Sea for Jeju?

According to our data for the last three years for Jeju the highest average sea water temperature was in August, September and July.

Average Water Temperature by Month, °F

Sea Water Temperature in August

Select Year: 2025 2024 2023

The average sea surface temperature in August 2025 for Jeju was 87.3°F. The maximum and minimum values were 83.6°F and 89.6°F respectively.

Sea Water Temperature in September

Select Year: 2025 2024 2023

The average sea surface temperature in September 2025 for Jeju was 86.1°F. The maximum and minimum values were 81.0°F and 89.6°F respectively.

Sea Water Temperature in July

Select Year: 2025 2024 2023

The average sea surface temperature in July 2025 for Jeju was 83.6°F. The maximum and minimum values were 76.2°F and 87.2°F respectively.

Best Time to Visit Jeju
The most sunny months:
May 15 days
October 14 days
April 14 days
The most warm months:
August 88.3 °F
July 85.5 °F
September 80.8 °F
Warmest sea temperature:
August 84.7 °F
September 80.5 °F
July 79.5 °F
The most cold months:
January 44.2 °F
February 45.9 °F
December 48.5 °F
The most rainy months:
August 8 days
September 7 days
July 7 days
The most windy months:
January 14 mph
December 14 mph
February 14 mph

Jeju on the Weather Map

South Korea Resorts:
NAME
Busan +76
Incheon +78
Jeju +78
Muju +80
Seoul +84
Yongpyong +86
24 Hours Weather Forecast
Jeju
Local time: 11:50
05 jul, sunday
1200 78°F
NE
8 mph
1500 76°F
NE
6 mph
1800 76°F
E
6 mph
2100 76°F
NE
7 mph
06 jul, monday
0000 74°F
NE
9 mph
0300 74°F
NE
7 mph
0600 74°F
NE
7 mph
0900 82°F
NE
4 mph