Despite increasing evidence of intensification of extreme precipitation events associated with a warming climate, the magnitude of extreme river flows is decreasing in many parts of the world. To better understand the range of relationships between precipitation extremes and floods, we analyzed annual precipitation extremes and flood events over the Contiguous United States from 1980 to 2014. A low spatial correlation (less than 0.2) between changes in precipitation extremes and changes in floods was found, attributable to a weak causal relationship. The co-variation between precipitation extremes and floods is also substantially low, with a majority of catchments having a coefficient of determination of less than 0.5, even among the catchments with a relatively strong causal relationship. The findings indicate a need for more investigations into causal mechanisms driving a non-linear response of floods to intensified precipitation extremes in a warming climate.