From National Center for Environmental Information:
The 2015 annual average U.S. temperature was 54.4°F, 2.4°F above the 20th century average, the second warmest year on record. Only 2012 was warmer for the U.S. with an average temperature of 55.3°F. This is the 19th consecutive year the annual average temperature exceeded the 20th century average. The first part of the year was marked by extreme warmth in the West and cold in the East, but by the end of 2015, record warmth spanned the East with near-average temperatures across the West. This temperature pattern resulted in every state having an above-average annual temperature.
Direct to Annual 2015 U.S. Climate Report
Direct to Animation: 2015 National Temperature Recap
See Also: Billion-dollar Weather and Climate Disastes (2015)
See Also: December 2015 Climate Summary and Annual Recap (2015)
See Also: U.S. Climate Extremes (2015)