Rainfall in Australia is highly variable due to the influence of five external climate drivers: the El Nino Southern Oscillation, the Indian Ocean Dipole, the Southern Annular Mode, atmospheric blocking and the Madden-Julian Oscillation. This paper argues that there is a strong correlation between the outbreak of warfare between Aborigines and British soldiers and settlers in inland New South Wales from 1824 to 1841 and droughts resulting from external climate drivers. Warfare on both sides became more bitter as pasture and water became scarcer, culminating in events such as the Myall Creek massacre in 1838 and William Lee's attack on Wiradjuri on the Bogan River in 1841.