NOAA's National Climatic Data Center (NCDC) late this morning confirmed that spring 2012 (March-May) temperatures crushed the seasonal heat record, as preliminary CapitalClimate analysis had previously indicated. The final average of 57.1° was equal to the average of earlier estimates and was the largest departure from the long-term average of any season on record since national data began in 1895.
As the map shows, every state east of the Rockies had a top-3 warmest spring, and 31 of those, from New England to the Northern Plains and from the Great Lakes to the Gulf Coast, had an all-time warm record.
From the NCDC report:
The national temperature of 57.1 degrees F during spring was 5.2 degrees F above the long-term average, besting the previous warmest spring of 1910 by 2.0 degrees F. This marked the largest temperature departure from average of any season on record for the contiguous United States. The spring of 2012 was the culmination of the warmest March, third warmest April, and second warmest May. This marks the first time that all three months during the spring season ranked among the ten warmest, since records began in 1895.
Record and near-record warmth dominated the eastern two-thirds of the nation during spring. Thirty-one states were record warm for the season, and 11 additional states had spring temperatures ranking among their ten warmest. Only Oregon and Washington had spring temperatures near their average.