temperature anomaly.” That is the difference between the long-term average temperature (sometimes called a reference value) and the temperature that is actually occurring. In other words, the long-term average temperature is one that would be expected; the anomaly is the difference between what you would expect and what is happening. - See more at: http://ete.cet.edu/gcc/?/globaltemp_anomalies/#sthash.Zhkfaayd.dpuf