Portsea Sea Temperature
Looking to find out what the sea water temperature in Portsea is for today and the next few days? Below are data and charts that will give you information about sea temperatures in Portsea and nearby locations.
Water temperature in Portsea right now
Below is the current sea temperature for Portsea, Australia on 25th March 2025.
18.87° C
(65.96° F)
- yesterday: 18.9° C (66.02° F)
- a week ago: 20° C (68° F)
At this temperature, water will feel cold compared to a swimming pool, but with a bit of experience and practice most people will find the water relatively comfortable to swim in.
The average sea temperature for Portsea on March 25th over the last 10 years is 18.29° C (64.93° F), with a low temperature of 17.25° C (63.05° F) and a high of 19.88° C (67.78° F).
Analysis and forecast for Portsea water temperatures
The water temperature in Portsea today is higher than the average temperature of 18.29° C (64.93° F) and the temperature on this day last year, 25th March 2024, was 18.86° C (65.95° F).
The chart and table below shows the change in water temperature in Portsea over the last 30 days:
The actual nearshore temperatures may vary by several degrees and this can also be heavily affected by weather. Strong winds can cause cold, deep waters to replace the surface waters that had been warmed by the sun, and heavy rain can also reduce the temperature of the sea surface temperature as well.
Water temperature in Portsea by month
The chart below shows the monthly average water temperature in Portsea.
For more detailed information on how the sea temperature in Portsea changes for each month of the year, choose from the months below.
Portsea map and nearby water temperatures

Locations near Portsea
The highest temperature in Australia today is 30.82° C (87.47° F) in Port Hedland. The lowest is in Coffin Bay, where the temperature of the water is 16.25° C (61.25° F).
Why measure sea surface temperatures (SST) in Portsea?
The ocean covers about 71% of the Earth's surface, and scientists record the sea surface temperature (SST) of locations such as Portsea because they want to understand and learn how the ocean communicates with the atomosphere of Earth.
SST is one measure that provides information on the global climate, and it can be used to predict the weather in Portsea as well as atmospheric model simulations and to study marine ecosystems in the area.
Data source and citation
Raw data for the calculations made to find the sea surface temperature in Portsea comes from the National Oceanic and Atmospheric Administration (NOAA) and their 1/4° daily Optimum Interpolation Sea Surface Temperature.
The water temperature data is constructed by combining observations from different platforms (satellites, ships, buoys, and Argo floats) on a regular global grid. A spatially complete sea surface temperature map is then built by interpolating to fill in gaps in the data.
If you'd like to use any of the information above in the format it is presented, please use the citation tool below.
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"Portsea Sea Temperature". SeaTemperatures.net. Accessed on March 25, 2025. http://seatemperatures.net/australia-and-oceania/australia/portsea/.
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"Portsea Sea Temperature". SeaTemperatures.net, http://seatemperatures.net/australia-and-oceania/australia/portsea/. Accessed 25 March, 2025
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