Newcastle Sea Temperature
Looking to find out what the sea water temperature in Newcastle is for today and the next few days? Below are data and charts that will give you information about sea temperatures in Newcastle and nearby locations.
Water temperature in Newcastle right now
Below is the current sea temperature for Newcastle, Australia on 15th December 2025.
22.59° C
(72.67° F)
- yesterday: 22.26° C (72.07° F)
- a week ago: 22.29° C (72.12° F)
Water at this temperature is very pleasant to swim in and if you tend to wear a wetsuit when swimming, you might consider removing it now to avoid the body overheating.
The average sea temperature for Newcastle on December 15th over the last 10 years is 21.09° C (69.96° F), with a low temperature of 19.55° C (67.19° F) and a high of 22.91° C (73.24° F).
Analysis and forecast for Newcastle water temperatures
The water temperature in Newcastle today is higher than the average temperature of 21.09° C (69.96° F) and the temperature on this day last year, 15th December 2024, was 22.57° C (72.63° F).
The chart and table below shows the change in water temperature in Newcastle 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 Newcastle by month
The chart below shows the monthly average water temperature in Newcastle.
For more detailed information on how the sea temperature in Newcastle changes for each month of the year, choose from the months below.
Newcastle map and nearby water temperatures
Locations near Newcastle
The highest temperature in Australia today is 31.24° C (88.24° F) in Broome. The lowest is in Bruny Island, where the temperature of the water is 15.25° C (59.46° F).
Why measure sea surface temperatures (SST) in Newcastle?
The ocean covers about 71% of the Earth's surface, and scientists record the sea surface temperature (SST) of locations such as Newcastle 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 Newcastle 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 Newcastle 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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<a href="http://seatemperatures.net/australia-and-oceania/australia/newcastle/">Newcastle Sea Temperature</a>
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"Newcastle Sea Temperature". SeaTemperatures.net. Accessed on December 15, 2025. http://seatemperatures.net/australia-and-oceania/australia/newcastle/.
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"Newcastle Sea Temperature". SeaTemperatures.net, http://seatemperatures.net/australia-and-oceania/australia/newcastle/. Accessed 15 December, 2025
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