I’m with Richard.
Each month, the US National Climatic Data Center calculates Earth’s average surface temperature using temperature measurements that cover the Earth’s surface. Then, another average is calculated for each month of the year for the twentieth century, 1901-2000. For each month, this gives one number representative of the entire century. Subtract this overall 1900s monthly average – which for February is 53.9F (12.1C) – from each individual month’s temperature and you’ve got the anomaly: that is, the difference from the average.
The last month that was at or below that 1900s average was February 1985. Ronald Reagan had just started his second presidential term and Foreigner had the number one single with “I want to know what love is.” More here