More importantly, the R2 values between QMAX trends and precipitation extreme trends are less than 0.2 across all precipitation extreme metrics. This result means that the spatial variation of precipitation extreme trends can explain less than 20% of the spatial variation of QMAX trends across the CONUS from 1980 to 2014. The R2 calculated over individual water resources regions (Figure 2e; also see Figure S2 of the Supporting Information) also indicates a low correlation. Specifically, more than 60% of the regions having an R2 value of less than 0.2, indicating the limitation of using trends of precipitation extremes to infer trends of floods.