Annual average rainfall is approximately 3500mm (137 inches) and is strongly seasonal, with 70% falling during the wet season which runs from December to April. Summers are often hot and humid, with the mean daily temperature in January around 28°C (82°F). However, temperatures up to 36°C (97°F) are not unusual during the summer months. Winters are mild and dry with the mean daily temperature in July around 22°C (72°F).
Northern Australia is subject to tropical cyclones in the wet season and their occurrence is unpredictable. The impact of these severe tropical storm systems are regarded as a natural phenomenon and a key evolutionary factor in shaping the ecology of Queensland's tropical lowland rainforests.
The vegetation at the Daintree Rainforest Observatory is complex mesophyll vine forest. There are a large range of botanical structural features represented including buttress and spur roots, a tall but irregular canopy with indistinct stratification of sub-canopy (saplings, seedlings, and ground cover layers) and irregular stem diameters. Also prominent on the site are a variety of robust woody lianas, vascular epiphytes, palms (both feather and fan), zingibers and aroids. The canopy is irregular, varying from 25 to 40 metres (82 to 131 feet), with dominant canopy trees belonging to Proteaceae, Meliaceae, Sapindaceae, Apocynaceae, Lauraceae, and Myrtaceae families.
The surrounding forests support around seven hundred species of vertebrates, a number of which are endemic. Mammals observed on the site include striped possum, Bennett's tree-kangaroo, prehensile-tailed rat, long-tailed pygmy possum, giant white-tailed rat, Cape York and bush rats, fawn-footed Melomys, long-nosed bandicoot, and a variety of bats.
A wide range of birds including several dove species, five species of honeyeaters, Victoria's riflebird, orange-footed scrubfowl, spotted catbirds, lesser sooty owls, ospreys, grey and brown goshawks, and parrots have been recorded at the site.
Also present on site are several frog species and reptiles including Boyd's forest dragon, eastern water dragon, carpet and amethystine pythons, and two colubrid snakes.