Why do the climates of northern and southern parts of the Northern Territory differ?

The climate of the Northern Territory varies significantly from north to south primarily due to the diminishing influence of the northwestern monsoon as one moves away from the coast.1

The northern region, often called the "Top End," experiences a tropical, monsoonal climate characterized by high humidity and significant rainfall, which can reach 60 inches (1,525 mm) annually. This area is heavily influenced by the monsoon, which brings a wet summer season from November to April.12

In contrast, the southern parts of the territory, known as the "Centre," are semiarid. As the influence of the monsoon wanes toward the southeast, annual rainfall drops significantly—to as low as 5 inches (130 mm)—and the region becomes increasingly dependent on tropical thunderstorms for precipitation. Consequently, while the north remains free from frosts, the southern interior experiences greater temperature fluctuations, such as the cooler winter temperatures recorded in Alice Springs compared to Darwin.31