Flood insurance take‐up remains low outside of the 100‐year flood zone (SFHA), where purchasing insurance is entirely voluntary, despite the availability of affordable policies. Merging building footprints and inundation data for a large‐scale flooding episode, we document substantial flood risk in the periphery of the SFHA and show that the storm led to large increases in take‐up. But, while in the SFHA, the increase vanished after 3 years, it was highly persistent in the periphery. The extent of flooding and the type of policies purchased indicate that periphery residents who experienced flooding for the first time revised upwardly their beliefs about flood risk and began purchasing flood insurance. We also argue that increased granularity in flood risk communication could increase take‐up before catastrophic flooding occurs.