Currently there isn't one available (unless, apparently, you're in Australia).
Best time really depends on what you're looking for hours-wise, weather-wise and crowd-wise. Smallest crowds would be Jan, Feb (avoiding holiday weekends of course), early Dec, Sept after school starts, and Nov (avoiding Thanksgiving week). Usually the park is open late on weekends because there is a large local customer base (many with APs). In Sept there tends to be a lot of rides down for refurb or holiday overlays. Warmest (read really hot) weather is July, August and Sept. Granted it's not humid like WDW, but it's still blistering. Rainy season tends to be Jan, Feb, March (tell that to the storms that have hit us last week and are coming this week), but it can rain in Nov, Dec, and April. When it rains, it's not for an hour or so, but for days usually. Also the rainy season can be the windy season and we get Santa Ana winds (which also tend to last for days). At first they're hot, but once there's snow in the passes, they get really cold. DL is not close to any passes/canyons that are wind accelerators, but I'm sure they get the wind too.
