The Ian Thorpe Aquatic Centre is super close to Pyrmont, Glebe, Chinatown & Darling Harbour, and is a great spot if you're keen to swim some laps, regardless of the outside weather or time of day.
The pool is temperature controlled, and fully undercover when it's raining (or worse!).
The pool hosts swimming lessons, swim squad training & group fitness classes in the Gym. There's also a spa & sauna to relax after a workout.
Operating hours are;
Monday to Friday: 6am to 9pm
Weekends and public holidays: 6am to 8pm
Closed on Good Friday and Christmas Day.