Yearly Temperature Fluctuations (IMAGE) University of Washington Caption The Sesan, Srepok and Sekong rivers had sensors that monitored river temperature year-round between 2004 and 2011. Before 2009 (labeled in blue), all three rivers had a similar temperature pattern: The water started to warm up at the beginning of the dry season, around November or October, and then cooled off once the wet season started in April or May. But after 2009 (labeled in red) the Sesan and the Srepok rivers, which had major dams built during that time, stayed cool year-round. Credit Bonnema et al./Environmental Research Letters Usage Restrictions For reuse with appropriate credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.