Steamy South (IMAGE) Columbia Climate School Caption Areas in the U.S. Southeast where heat/humidity mixtures have driven temperatures to 'wet-bulb' readings of 31 degrees C (equivalent to 125 degrees F on the "real feel" heat index). Green markers show one occurrence from 1979-2017; orange, 3; red, 10. Credit Colin Raymond Usage Restrictions Credit must be given. 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.