People have often heard statements like "2010 is the hottest year on record in the world." However, this ranking in order of average global temperature is uncertain, because the global temperature is not a direct measurement but a statistical combination of data, which by itself has uncertainty. We have developed new methods to rank each year taking into account the standard error of a real mean temperature. The methods give us distributions of the rank of each year's temperature, and allows us to compute the probability that a given year is the hottest year on record. We can arrange the years in order of these probabilities. The results are consistent with regular ranking of continental US annual mean temperature, but allows us to express the uncertainty of the ranks. We can also estimate, for example, the probability that 12 of the last 15 years have been among the hottest ever, as President Obama said in his State of the Union address in February.