Do natural shocks increase insurgent rates of civilian victimization? We consider one case of a natural shock that directly affected an ongoing rebellion, Mozambique’s Cabo Delgado insurgency, where in recent years an insurgency with few societal ties and an extremist, pro-Islamic State ideology has engaged in multiple attacks on civilians. Our assessment employs both time series analysis and qualitative evaluations. Our focus is on the effects of cyclones—a climatic event whose rates are predicted to intensify over the coming decades—on this insurgency’s use of violence against civilians. In contrast to several past studies of natural shocks in conflict zones and strategic violence against civilians, our findings suggest that in contexts of insurgencies that do not have a strong local support base and where the group purports an extremist transnational ideology, natural shocks may lead to more violence against civilians.