Preliminary analysis of weather data gathered from more than 1,200 sites across the continental United States indicates that last year was the warmest on record.
The average temperature for 2006 was 12.8°C (55°F), National Oceanic and Atmospheric Administration (NOAA) scientists reported on the agency's website Jan. 9. That's about 1.2°C above the average temperature for the 20th century and 0.04°C warmer than the previous yearly record, set in 1998, says Richard Heim, a meteorologist at NOAA's National Climatic Data Center in Asheville, N.C.
That year began during the strongest El Niño ever recorded (SN: 12/11/99, p. 374: http://www.sciencenews.org/pages/sn_arc99/12_11_99/fob5.htm). Changes in weather patterns during El Niños typically warm winter temperatures across much of North America.