Riverine heat waves on the rise, outpacing air heat waves

Riverine heat wave events—periods of abnormally high riverine water temperatures (WT)—can substantially impair aquatic ecosystems, water quality, and food and energy production. However, comprehensive analysis of riverine heat waves is still emerging, long hindered by fragmented and discontinuous WT data. Here, we used a deep learning model and reconstructed consistent daily WT in 1471 U.S. river sites (1980–2022). Results show that riverine heat wave events occur less frequently and intensively but last nearly twice as long as air heat waves. Alarmingly, riverine heat waves have risen at much faster rates than air heat waves. Results here underscore the need for coordinated monitoring and data consolidation efforts for riverine heat waves, and their incorporation into global climate risk assessment and adaptation policies.