It's going to have to be a lot bigger than Australia if you want all of these climates in the same continent. Jungles are tropical climates (year-round average temperature 18C or above): assuming your planet is comparable to Earth, the latitude for that would be 20N or less (or up to 20S, but if you want tundra to the north you're definitely in the northern hemisphere). Tundra, by contrast, needs an average temperature of less than 10C year-round, with a lot of time spent below 0C. Looking at Earth, there's a minimum of 30 degrees of latitude between those two climates, more often 40 degrees.
As for your jungles being due west of your temperate forest, that doesn't quite add up. You're going to need to change that to southwest, most likely. You could also change the jungle to being on the eastern side and divide the two forests by a mountain range (the tectonics that would create a mid-continent mountain range are left as an exercise for the reader). Position your continent correctly (the southern edge being on the equator), and you should end up with a cold ocean current on the west side versus a warm one on the eastern edge, which would lower temperatures and rainfall to the west: this does risk creating a desert to the west, however, if you're not careful.
There might be some ways to work around the scale problem as well. Raising the altitude in the northern areas could let you create a tundra farther south than normal, if you're willing to have tundra limited to areas two thousand metres or more above sea level.
I'm not an expert on weather, but keep in mind that jungle climates are effectively by definition unable to ever receive snowfall; if it's anywhere near cold enough for snow, it's too cold to be tropical and thus is not a jungle. Snowfall starting up in September also seems rather early; if you give your planet a larger axial tilt, you might have that at a reasonable altitude, but that is not conducive to having tropical regions.