2006 Sets Record for Warmest Year Across USA
The 2006 average annual temperature for the Lower 48 United States was the warmest on record and nearly identical to the record set in 1998, according to government scientists at the National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Center in Asheville, NC.
Meteorologists said the last nine years all have been among the 25 warmest years on record for the contiguous U.S., a streak that is unprecedented in the historical record.
Seven months in 2006 were much warmer than average, including December, which ended as the fourth warmest December since records began in 1895, says the agency.
Based on preliminary data, the 2006 annual average temperature was 55 degrees Fahrenheit. That is 2.2 degrees F (1.2 degrees C) above the 20th- century mean and 0.07 degrees F (0.04 degrees C) warmer than 1998.
These values were calculated using a network of more than 1,200 U.S. Historical Climatology Network stations. The data, primarily from rural stations, have been adjusted to remove artificial effects resulting from factors such as urbanization and station and instrument changes that occurred during the period of record.
An improved data set being developed at the National Climatic Data Center and scheduled for release in 2007 incorporates recent scientific advances that better address uncertainties in the instrumental record.
Although undergoing final testing and development, this new data set also shows 2006 and 1998 to be the two warmest years on record for the contiguous states, but with 2006 slightly cooler than 1998.
Five states had their warmest December on record–Minnesota, New York, Connecticut, Vermont, New Hampshire–and no state was colder than average in December.
The unusually warm start to this winter reflected the rarity of Arctic outbreaks across the country as an El Nino episode continued in the equatorial Pacific. It is known that El Nino is playing a major role in this winter’s short-term warm period.
U.S. and global annual temperatures are now approximately 1.0 degrees F warmer than at the start of the 20th century, and the rate of warming has accelerated over the last 30 years, increasing globally since the mid-1970s at a rate approximately three times faster than the century-scale trend.