Kinda warm? It's hot in Feb!
It will be hard to avoid the heat then. Feb is usually Sydney's hottest month. Up north it is well into the monsoonal season.
However, all is not lost. If you plan to fly early and avoid the build ups you'll be fine. By early I mean plan to be airborne by 8 or 9 and be on the ground by 2ish.
By heat, Sydney temps. Ave 26 deg C Humidity about 60%. (you can be unlucky and get a cool patch (`22 deg C). Cairns = 33 deg C humidity about 80%! Drink lots of water, carry lots of water when flying. Have a look at .
Bureau of Meteorology for more weather info.
Go to the CASA website and have a look. I know you can get a temporary permit based on your JAR one. I think a medical and a checkride is necessary. Expect a checkride any way before hiring a plane. Now, Oz isn't the mega slack country some people think it is. You will have to demonstrate that you can navigate. So, revise your skills (on the ground) before spending any of your hard earned cash. Trust me, if you do it properly the skills you'll gain will help you when you go for your CPL.
Also remember, you have to have fun