Past 12 months and first third of the year were warmest nation has experienced
Commerce's National Oceanic and Atmospheric Administration (NOAA) reports that several warm periods across the contiguous U.S. during April brought the national average temperature to 55°F, 3.6°F above average, marking the third warmest April on record. These temperatures, when added with the first quarter and previous 11 months, calculate to the warmest year-to-date and 12-month periods since recordkeeping began in 1895.
January-April was the warmest such period on record  for the contiguous United States, with an average temperature of 45.4°F, 5.4°F above the long-term average. Twenty-six states, all east of the Rockies, were record warm for the four-month period and an additional 17 states had temperatures for the period among their ten warmest.
On the heels of the warmest March  for the U.S., warmer and drier than average temperatures continued for much of the nation with some states in the Ohio Valley having a small, but still above-average, dip in temperatures. Full briefing