River flood risks are expected to rise as climate change intensifies the global hydrological cycle and more people live in floodplains. Changing risk may be revealed by trends in flood frequency, magnitude, or seasonality, as well as by shifts in the mechanisms that generate inundations. However, detection and attribution of climate signals in flood records is often hampered by brief, incomplete, or poor-quality flood data. Additionally, it can be difficult to disentangle the effects of changing climate, land cover, channel morphology, and human activities.