The preliminary national climate review for November from the National Climatic Data Center (NCDC) shows that the U.S. is virtually certain to set a record for warmest yearly average temperature in 2012. Although November was only the 20th warmest on record (tied with 2004), the accumulated warmth so far this year means that December would have to be the coldest on record by a wide margin to avoid setting a new annual record. How likely is that? Through the first 5 days of this month, there have been over 1100 record high temperatures set or tied in the contiguous 48 states, vs. only 3 record lows. This means that the remaining days of the year would have to be even more spectacularly cold to bring the average down to the old record. According to the latest extended forecast from the Climate Prediction Center, however, the odds that December will be warmer than average through the first 3 weeks are quite good.
The highlights from the NCDC:
The average temperature for the contiguous U.S. during November was 44.1°F, 2.1°F above the 20th century average, tying 2004 as the 20th warmest November on record.
November brought warmer-than-average conditions to the western half of the country. The largest temperature departures from average were centered near the Rockies where Arizona, Colorado, New Mexico, Utah, and Wyoming had November temperatures among their ten warmest.
The Eastern Seaboard, Ohio Valley, and Southeast were cooler than average during November. North Carolina tied its 10th coolest November on record, with a statewide-averaged temperature 3.5°F below average.
The January-November period was the warmest first 11 months of any year on record for the contiguous United States. The national temperature of 57.1°F was 3.3°F above the 20th century average, and 1.0°F above the previous record warm January-November of 1934. During the 11-month period, 18 states were record warm and an additional 24 states were top ten warm.
It appears virtually certain that 2012 will surpass the current record (1998, 54.3°F) as the warmest year for the nation. December 2012 temperatures would need to be more than 1.0°F colder than the coldest December (1983) for 2012 to not break the record.