…but the coolest summer nights have warmed by 5 deg. F. John Christy and I continue to examine U.S. air temperature trends, especially those in summer, and John has recently been looking at “heat wave” statistics. My interest is in determining how much the urban heat island (UHI) effect has impacted reported warming trends. Last … Continue reading The Hottest Summer Days in D.C. Have Not Gotten Hotter in Last 40 Years