Rainfall varies across the area drained by the Macquarie River. The mountain the peaks and tablelands receive higher rainfall due to the shadowing effects of the surrounding ranges. The Great Dividing Range area receives between 750 to 900 mm annual median rainfall. This is falls evenly throughout the year. Gaps in the Dividing Range allows moist easterly air to pass inland, annual median rainfall of 750 mm or more is experienced further westward. Further north-west it is drier, in the Castelreagh and middle portions of the Macquarie valleys the annual median rainfall is 300 to 400 mm.