Regionally, the Northeast, Southwest, South, and North West Central US posted record high annual temperatures, with the North West Central US coming in at 3.9 degrees F. above the long-term average, followed by the Northeast at 3.4 degrees F. above the long-term average.
Beyond temperatures, the continental US posted the second worst year, after 1998, for severe weather, as measured by the NCDC's US Climate Extremes Index.
The most pervasive severe conditions in 2012 centered on the ongoing drought in the US. At one point in July, moderate to exceptional drought, as measured by a gauge known as the Palmer Drought Severity index, covered 61 percent of the US. Other measures still put the drought coverage at 61 percent of the country, covering most of the western two-thirds of the US.
Toward the end of last year, a dearth of water flowing into the Mississippi River threatened to shut down barge traffic along a key section between St. Louis and Cairo, Ill. But the US Army Corps of Engineers released water from the Carlyle Lake Reservoir in Illinois, which fed water into the river. The Army Corps also used explosives to pulverize rocks on the river bottom that had become threats to navigation as the water level fell. These two actions, Corps officials say, are expected to keep the Mississippi open to barge traffic through the end of January.