Hot and often humid down the east coast; Sydney averages a 26°C daily maximum in January. It is peak domestic holiday season, so coastal New South Wales and the Gold Coast are at their busiest and most expensive. In the tropical north it is the wet season, when Cairns sees monsoon rain, marine stinger nets go up on the beaches and reef visibility can drop.

Warm days, cooler nights and thinning crowds in the south. Melbourne and the Great Ocean Road are at their most comfortable, and the tropical wet eases from around April, which makes late autumn a strong window for pairing the reef with the southern cities.

Sydney's coolest month is July, averaging a 16.4°C daily maximum, and the coast rarely sees frost. This is the dry season in Queensland and the Northern Territory — the most reliable window for the Great Barrier Reef and for Uluru, where days are mild but desert nights fall close to freezing.

Mild and settled in the south, with humpback whales migrating along the east coast and comfortable walking weather at Uluru before the summer heat arrives. Reef conditions in the north are still good and school-holiday crowds have not yet peaked.