While evidencemounts that indigenous burninghas a significant role in shaping pyrodiversity, theprocesses explainingits variationacross local andexternalbiophysical systems remain limited. This is especially the case with studies of climate-fire interactions, which only recognize an effect of humans on the fire regimewhen theyact independentlyof climate. In this paper, we test the hypothesis that an anthropogenic fire regime (fire incidence, size and extent) does not covary with climate. In the lightning regime, positive El Nin˜ o southern oscillation (ENSO) values increase lightning fire incidence, whereas La Nin˜ a (and associated increases in prior rainfall) increase fire size. ENSO has the opposite effect in the Martu regime, decreasing ignitions in El Nin˜ o conditions without affecting fire size. An thropogenic ignition rates covary positively with high antecedent rainfall, whereas fire size varies only with high temperatures and unpredictable winds, which may reduce control over fire spread. However, total area burned is similarly predicted by antecedent rainfall in both regimes, but is driven by increases in fire size in the lightning regime, and fire number in the anthropogenic regime. We conclude that anthropogenic regimes covary with climatic variation, but detecting the human-climate-fire interaction requires multiple measures of both fire regime and climate. [ABSTRACT FROM AUTHOR]