Hi Sara,
I use the following, and they are generally close to reality.
Clear outside
http://clearoutside.com/forecast/-33.34/151.16
7Timer
http://202.127.24.18/index.php?produ...g=en&tzshift=0
(however, 7timer seems to be "down" on the odd occasions)
and Accuweather for astronomy
http://www.accuweather.com/en/au/glo...st/13014?day=6
... and take the average consensus.
Clear Skies