From these hills which catch the first downpour of the rains from the ocean, the ground falls eastward.
It is this tropical downpour that fills and floods the rivers flowing into Lake Eyre and those falling into the Darling on its right bank.
The climate is practically unchanging all the year round, the atmosphere being uniformly moist, and though days of continuous downpour are rare, comparatively few days pass without a shower.
The number of rainy days throughout the peninsula varies from 160 to over 200 in each year, but violent gusts of wind, called " Sumatras," accompanied by a heavy downpour of short duration, are more common than persistent rain.
The sudden swelling of rivers and downpour of rain stopped all movement at once, and the "Mud March" came to an end.