Flood early warning systems play a major role in the disaster risk reduction paradigm as cost-effective methods to mitigate ﬂood disaster damage. The connections and feedbacks between the hydrological and social spheres of early warning systems are increasingly being considered as key aspects for successful ﬂood mitigation. The behavior of the public and ﬁrst responders during ﬂood situations, determinedby their preparedness, is heavily inﬂuenced by many behavioral traits such as perceived beneﬁts, risk awareness, or even denial. In this study, we use the recency of ﬂood experiences as a proxy for social preparedness to assess its impact on the efﬁciency of ﬂood early warning systems through a simple stylized modeland implemented this model using a simple mathematical description. The main ﬁndings, which are basedon synthetic data, point to the importance of social preparedness for ﬂood loss mitigation, especially in circumstances where the technical forecasting and warning capabilities are limited. Furthermore, we foundthat efforts to promote and preserve social preparedness may help to reduce disaster-induced losses byalmost one half. The ﬁndings provide important insights into the role of social preparedness that may helpguide decision-making in the ﬁeld of ﬂood early warning systems.