Average water temperature on Manly Beach in summer?

Does, by any chance, anyone have the information on what is the average temperature of water on Manly Beach, but in summer? My friend claims that it is almost 80 degrees Fahrenheit, but to me it really does sound unbelievable, so I would like to hear a neutral opinion, or a fact.

As far as I know the average water temperature on Manly Beach in summer is around 22 degrees Celsius, which is definitely less than 80 degrees Fahrenheit, so I guess that your friend was not very well informed. If you want, or if you don’t trust me, check it anywhere on the internet.