The climate of Muswellbrook and the Upper Hunter is characterised by warm dry summers and cool, dry winters.  In summer the weather in the Muswellbrook region is dominated by synoptic high pressure systems which alternate with low pressure systems - “southerly busters”, every three to five days.  Rainfall is highest in the summer months (Hyde et al, 1981), usually as the result of thunderstorms.

In winter the mid-latitude westerlies and high-pressure systems alternating with cold fronts modify the climate.  The prevailing winds are north-westerly and are created via cold air drainage flows associated with the terrain.  Winter is drier than summer, with regular frosts and fogs occurring from mid-autumn to late spring.

Average Historical Temperature is 30 degrees C.

Average Historical Rainfall is 700mm per year.