NOAA: July 2010 Hotter Than Normal

August 16, 2010

The July 2010 average temperature for the contiguous United States was 75.5 degrees F, or 1.3 degrees F, (17th warmest) above the 1901-2000 long-term average, according to the latest NOAA State of the Climate report. Last month’s average precipitation was 3.24 inches, or 0.48 inch above the 1901-2000 average.

Based on records dating back to 1895, this monthly analysis, prepared by scientists at NOAA’s National Climatic Data Center in Asheville, N.C., is part of the suite of climate services NOAA provides.

U.S. Temperature Highlights: July 2010

(Credit: NOAA)

•The intense heat either tied, or shattered, July monthly temperature records in several East Coast cities. Washington D.C. recorded an average temperature of 83.1 degrees F, which tied with July 1993 as the warmest for any calendar month on record. Other July monthly temperature records were broken, or tied, in Atlantic City, N.J. and Hartford, Conn.

•It was the hottest July on record for Delaware and Rhode Island. Along the East Coast, each state from Maine to Florida ranked in their top 10 warmest. Only Montana, Idaho, and Texas had below-normal average temperatures for the month.

•The Southeast and Northeast climate regions experienced their third and fifth warmest July on record, respectively. Of the nine climate regions within the contiguous U.S., none experienced a below normal average temperature.

The May-July period was the warmest on record for the Northeast

•The May-July period was the warmest on record for the Northeast and Southeast climate regions and was the ninth warmest for the Central region. This period produced record warmth for: New Hampshire, Massachusetts, Rhode Island, New Jersey, Delaware, Maryland, Virginia, North Carolina, and South Carolina. The Northwest had its sixth coolest May-July period. Below-average temperatures were experienced in Oregon (fifth coolest), Idaho (seventh), and Montana (eighth) during the same period.

•In the Southeast, the below average temperatures from the winter were still evident in the year-to-date (January-July) period, as Texas, Louisiana, Mississippi, Alabama, Georgia, and Florida were below normal. Meanwhile, Maine, New Hampshire, Vermont, Rhode Island, and Connecticut have experienced a record warm start to the year, resulting in a record warm year-to-date for the Northeast climate region.

U.S. Precipitation Highlights: July

(Credit: NOAA)

•Wisconsin had its second wettest July, while Texas had its fourth, Iowa its fifth, and Missouri its eighth. By contrast, it was the 10th driest July for Georgia and Virginia.

•Much of the Plains and Upper Midwest experienced above normal precipitation, triggered by moist tropical air that fueled widespread thunderstorms. Several of these systems stalled out and caused major flooding in some areas.

U.S. Precipitation Highlights: May through July and Year-to-Date

•From May through July, persistent rainfall made this period the wettest for Wisconsin, the second wettest for Illinois and Iowa, the third wettest for Michigan and fifth wettest for Washington State.

•Precipitation, when averaged across the nation, was much-above-normal, ranking as the 10th wettest May-July period. On the regional level, much of the northern tier United States was above normal. The East North Central had its second wettest May-July. Both the Central and West North Central region had their ninth wettest and the Northwest had its 10th.

•Precipitation was well below normal in Louisiana for the year-to-date period (January-July), as drought conditions continued to deteriorate. The state was more than 9.5 inches below the long-term average for the year, its seventh driest such period in 116 years. Conversely, Iowa was nearly 10 inches above average, its third wettest start to the year.

NCDC’s State of the Climate reports, which assess the current state of the climate, are released soon after the end of each month. These analyses are based on preliminary data, which are subject to revision. Additional quality control is applied to the data when late reports are received several weeks after the end of the month and as increased scientific methods improve NCDC’s processing algorithms.

Scientists, researchers and leaders in government and industry use NOAA’s monthly reports to help track trends and other changes in the world's climate. This climate service has a wide range of practical uses, from helping farmers know what and when to plant, to guiding resource managers with critical decisions about water, energy and other vital assets.