How Much Has Global Warming Changed July 4th Temperatures Over Washington State?

Walking my dog yesterday, I ran into a neighbor who asked whether July 4th temperatures in our area had changed much under global warming. I promised to run the numbers... and here are the results. Be prepared to be surprised 😀. Starting at Olympia, on the western side of the state, there is almost no trend in July 4 daily average temperatures since the 1940s! (The purple line is the linear…