Historical Temperatures (IMAGE) University of California - Berkeley Caption Using data from weather stations scattered throughout the U.S., climate researchers have created maps of the average annual temperature and rainfall totals at points approximately 800 meters apart over much of the United States. In this study, the team used these maps to calculate historical temperature and rainfall trends within the parks and over the U.S. as a whole. Credit Patrick Gonzalez Usage Restrictions with credit 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.