The graph at right shows long - term average monthly temperatures and the average temperatures of recent months. (ramblingsdc.net)
To find out how average monthly temperatures had changed from 1847 to 2013, the researchers used an advanced statistical time series approach to figure out what changes in temperature were due to natural variability and what changes represented a long - term trend. (scientificamerican.com)
Daily records from Manhattan's Central Park show that average monthly temperatures already increased by 3.6 degrees Fahrenheit from 1901 to 2000 — substantially more than the global and U.S. trends. (sciencedaily.com)