Climate Warming Map (IMAGE) University of Arizona Caption This map shows the observed difference between the average annual US temperatures (degrees F) for this century (2000 to 2009) and those of the last century (1900 to 1999). It is clear that the US has been much warmer in this century than the last, particularly in the West, and even more so in the Southwest and headwaters of the Colorado River. Credit NOAA Usage Restrictions Please use credit information. 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.