NOAA: October Warmer Than Average in the United States

Early season storm breaks October snowfall records across the Northeast, while record drought continues across the Southern Plains

Washington, DC–(ENEWSPF)–November 8, 2011

October 2011 precipitation "divisional rank" map.

October 2011 temperature “divisional rank” maps. High resolution (Credit: NOAA)

During October, a persistent upper-level weather pattern brought below-normal temperatures to the southeastern United States and above-normal temperatures from the Southwest, across the northern tier of the United States, and into parts of the Northeast. Near-normal precipitation during October across the Southern Plains made little change in long-term drought conditions. The drought stricken areas of the Southern Plains still need at least 18 inches of rain in a single month to end the on-going drought.

The average U.S. temperature in October was 55.7 degrees F, 0.9 degrees F above the 1901-2000 long term average. Precipitation, averaged across the nation, was 2.04 inches. This was 0.07 inch below the long-term average, with variability between regions. This monthly analysis, based on records dating back to 1895, is part of the suite of climate services NOAA provides.

U.S. climate highlights – October

  • The Southwest, much of the Northeast, and states along the U.S.-Canadian border experienced above-normal temperatures. Eighteen states had October temperatures above their long-term averages.
  • Eleven states from Louisiana to West Virginia had October temperatures below their long-term averages. Meanwhile, states in the Pacific Northwest, the Central and Southern Plains, and parts of the Midwest had near average October temperatures.
  • An early season storm brought heavy snow accumulations to the Northeast on October 29-31. Several locations broke October snowfall records, including New York City’s Central Park, where 2.9 inches of snow accumulated. The highest snowfall amounts were further inland, with more than 30 inches accumulating in western Massachusetts and southern New Hampshire. The heavy, wet snow falling on the autumn foliage, combined with strong winds, caused havoc across the region. The storm received a preliminary rank of Category 1 on the Northeast Snowfall Impact Scale (NESIS), which takes into account snowfall accumulation in populated areas, making it the only ranking storm to occur during October on record. NOAA continues to assess the economic impact of this early season snow storm.
  • Several storms impacted the interior western states during October, bringing above normal precipitation totals to Idaho, Montana, Nebraska, Nevada, and Wyoming. Storms also impacted the eastern seaboard, causing wetter than normal conditions in Florida and the Northeast.
  • A string of states from Minnesota southward along the Mississippi River to Louisiana observed below normal precipitation. Eight states were drier than normal during October with Iowa, Louisiana, and Missouri each having their ninth driest October on record.
  • Dry and warm weather the first few weeks of October created ideal wildfire conditions across the Great Basin and Pacific Northwest, contributing to record acreage burned during the month. More than half a million acres burned nationwide during October, more than double the long-term average.
  • As of November 1, about nine percent of the contiguous United States remained in the worst category of drought, called D4 or exceptional drought, smaller than nearly 12 percent of the country experiencing exceptional drought at the beginning of the month. Slight improvement of drought conditions occurred across the Southern Plains during October, where near-normal precipitation was observed.

October 2011 precipitation "divisional rank" map.

October 2011 precipitation “divisional rank” map.High resolution (Credit: NOAA)

August-October and year-to-date

  • During the August-October period, the United States as a whole experienced much above normal temperatures with the nationally averaged temperature of 66.0 degrees F ranking as the 10th warmest August-October on record.
  • This same three month period brought very warm temperatures to the western half of the country, where 10 states experienced temperatures among their 10 warmest for the period, including Texas, which was record warm. The Northeast was also particularly warm, where eight states had a top 10 warm August-October. Below-normal temperatures were present for parts of the Ohio Valley and Gulf Coast.
  • Precipitation was a mixed bag during the August-October period, with record wet conditions across the Northeast, and much drier than normal conditions across the central United States. Maryland, New Jersey, New York, Pennsylvania, and Vermont had a record wet August-October period, and seven other states in the region had precipitation totals among their 10 wettest.
  • For the first 10 months of 2011, the contiguous United States was warmer than average. Above-normal temperatures were present across the southern tier of the country, and along the eastern seaboard. Texas was record warm for the 10 month period, while Delaware, Maryland, New Jersey, New Mexico, and Oklahoma had temperatures ranking in their top 10 warmest.
  • As a whole, the January-October period brought near normal precipitation to the United States, but there was significant regional variability. States across the Northeast were record wet, including Connecticut, Massachusetts, New Jersey, New York, Ohio, Pennsylvania, and Vermont. Drier than normal conditions prevailed across the southern tier of the country, with record dry conditions reported for Texas.

NCDC’s monthly reports 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 new scientific methods improve NCDC’s processing algorithms.

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Source: noaa.gov