Summer 2012 was the third hottest summer on record for the contiguous United States since recordkeeping began in 1895. According to the latest statistics from NOAA’s National Climatic Data Center, the average temperature for the contiguous United States between June and August was over 74° Fahrenheit, which is more than 2° F above the twentieth-century average. Only the summers of 2011 and 1936 have had higher summer temperatures for the Lower 48.
These maps show patterns of temperature (above) and precipitation (below) across the United States from June through August 2012 compared to the recent long-term average (1981-2010). The summer season was warmer than average for a large portion of contiguous United States, with the Southeast and parts of the Northwest being exceptions. Sixteen states across the West, Plains, and Upper Midwest had summer temperatures among their ten warmest. Colorado and Wyoming each had their record-hottest summer, and much of the Northeast was warmer than average, with seven states from New Hampshire to Maryland having a top-ten-warmest summer.
The U.S. Climate Extremes Index (USCEI), an index that tracks the highest and lowest 10 percent of extremes in temperature, precipitation, drought, and tropical cyclones across the contiguous U.S. was more than one and a half times the average value during summer 2012, and marked the eighth largest USCEI value for the season. Extremes in warm daytime temperatures, warm nighttime temperatures, and extremely dry conditions covered large areas of the Nation, contributing to the above-average USCEI value.
Source: NOAA NCDC