A comprehensive new study extending the U.S. Historical Climatology Network (USHCN) record back to 1899 finds that both hot and cold temperature extremes across the contiguous United States have declined over the past 127 years. The research, performed by Dr. John R. Christy, Alabama State Climatologist (retired) and professor of atmospheric and Earth science at The University of Alabama in Huntsville, analyzed more than 40 million daily temperature observations to provide the most complete long-term view to date of U.S. extreme heat and cold. The paper is published in Theoretical and Applied Climatology.