What natural feature primarily affects the dryness of Australia's interior?

The primary natural feature that affects the dryness of Australia's interior is indeed the deserts. Australia's interior is dominated by large desert landscapes, such as the Great Victoria Desert and the Great Sandy Desert. These areas receive very little rainfall due to their geographical location and climatic conditions. The interior regions are situated far from the moderating influence of the ocean, which means that they are less impacted by moisture-laden winds.

Deserts have unique characteristics that cause low humidity and limited vegetation, as they are areas where evaporation exceeds precipitation. This dry environment is a result of multiple factors, including high temperatures leading to greater evaporation and the presence of high-pressure systems that inhibit cloud formation and therefore rainfall. This combination makes the deserts a significant contributor to the overall arid nature of Australia's interior, creating a stark contrast to the more temperate and wetter coastal regions.