This data the coastal Cat Ba sea water temperature today, tomorrow and the upcoming days. Besides, you can also get information about the weather and surf forecast, as well as the data on sunrise / sunset and moonrise / moonset at a given point on any given day.
Water temperature in Cat Ba today is 30.2°C. Based on our historical data over a period of ten years, the warmest water in this day in the Gulf Of Tonkin near Cat Ba was recorded in 2020 and was 31.9°C, and the coldest was recorded in 2008 at 28.8°C. Sea water temperature in Cat Ba is expected to drop to 29.7°C in the next 10 days. September average water temperature in Cat Ba is 29.8°C, the minimum temperature is 27.5°C, and the maximum is 31.9°C.
The swimming season in Cat Ba lasts from January to December, twelve months per year! During those months, Cat Ba water temperature does not drop below 20°C and therefore suitable for comfortable swimming. The average water temperature in Cat Ba in winter reaches 20.2°C, in spring 24.2°C, in summer the average temperature rises to 30.2°C, and in autumn it is 27.7°C.
5 September 2025 |
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today temp |
30.2°C |
4 September 2025 |
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yesterday temp |
29.6°C |
The sea salinity in Cat Ba is 32.14‰, and the average salinity of the World Ocean is 35‰.
Another important indicators for a comfortable holiday on the beach are the presence and height of the waves, as well as the speed and direction of the wind. Please find below data on the swell size for Cat Ba. We calculate the swell size based on the mean wave height (trough to crest) of each third highest wave. For more information on surf forecasts for the next ten days, please visit sea state forecast Cat Ba. Data in table shown for 6 September 2025, time in GMT 0 format (you can change the time zone on the sea state forecast page)
0-3 h | 3-6 h | 6-9 h | 9-12 h |
---|---|---|---|
0' 5" | 0' 4" | 0' 4" | 0' 4" |
0.12 m | 0.11 m | 0.1 m | 0.1 m |
12-15 h | 15-18 h | 18-21 h | 21-24 h |
---|---|---|---|
0' 7" | 0' 7" | 0' 6" | 0' 6" |
0.17 m | 0.17 m | 0.16 m | 0.14 m |
Data in a table show Cat Ba temperature today (6 September 2025). For more information and forecast for a few days, go to the weather forecast Cat Ba.
0-3 h | 3-6 h | 6-9 h | 9-12 h |
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![]() | ![]() | ![]() | ![]() |
27.5°C | 27.1°C | 26.9°C | 29.7°C |
12-15 h | 15-18 h | 18-21 h | 21-24 h |
---|---|---|---|
![]() | ![]() | ![]() | ![]() |
30.9°C | 30.5°C | 28.5°C | 28.1°C |
You may also be interested in other sections of our site for Cat Ba: Sunrise and Sunset, Tides
These figures shows the average, minimum and maximum monthly sea temperature in Cat Ba. In addition to the table values, the graph below displays of changes average surface temperature during the year. Values are calculated based on the data over the past 10 years. Using them, you can check the water temperature in Cat Ba on any day of this period that interests you. Click on the month link and you will see a table for each day, or alternatively you can view the temperature curve of the month and select 2 different years you want to compare, either in a table or as a curve
Month | Avr | Min | Max | |
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January | 19.6°C | 17.2°C | 22.7°C | cold |
Sea water temperature in Cat Ba in January | ||||
February | 19.2°C | 16.7°C | 22.2°C | cold |
Sea water temperature in Cat Ba in February | ||||
March | 20.9°C | 17.2°C | 24.2°C | warm |
Sea water temperature in Cat Ba in March | ||||
April | 23.8°C | 19.6°C | 29.3°C | warm |
Sea water temperature in Cat Ba in April | ||||
May | 27.8°C | 24°C | 31.4°C | hot |
Sea water temperature in Cat Ba in May | ||||
June | 30°C | 27.6°C | 32.2°C | hot |
Sea water temperature in Cat Ba in June | ||||
July | 30.3°C | 28.3°C | 32.4°C | hot |
Sea water temperature in Cat Ba in July | ||||
August | 30.3°C | 28.2°C | 32.2°C | hot |
Sea water temperature in Cat Ba in August | ||||
September | 29.8°C | 27.5°C | 31.9°C | hot |
Sea water temperature in Cat Ba in September | ||||
October | 28°C | 25.2°C | 31.1°C | hot |
Sea water temperature in Cat Ba in October | ||||
November | 25.3°C | 22.4°C | 28.3°C | hot |
Sea water temperature in Cat Ba in November | ||||
December | 21.9°C | 18.3°C | 26°C | warm |
Sea water temperature in Cat Ba in December |