NCDC / Climate Monitoring / Climate of 2002 / October / U.S. Temperatures / Search / Help
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Climate of 2002 - October National Temperatures
National Climatic Data Center,
14 November 2002
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Global Analysis / Global Hazards / United States Overview / U.S. Drought / Extremes Use these links to access detailed analyses of Global and U.S. data.
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October Temperatures
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The graph to the left shows monthly mean temperature averaged across the contiguous United States based on long-term data from the U.S. Historical Climatology Network (USHCN). The value for 2002 is estimated from preliminary Climate Division data using the first difference approach. October 2002 ranked as the 14th coldest October in the 1895 to present record. The preliminary nationally averaged temperature was 52.6� F (11.4� C) which was 2.2� F (1.2� C) below the long-term mean.
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Much below average warmth occurred in 12 contiguous states in October. No statewide mean temperature records were set for the month, though Minnesota and South Dakota had their third coldest October since 1895 and both states had their coldest October since 1925. Only one state (Florida) had much above average temperatures for the month while 6 other southeastern states had significantly above average temperatures and 9 states out of the lower 48 states had near average temperatures.
As can be seen in a map of divisional temperature (below right), significantly warmer than average temperatures were evident in all but one Gulf coast division, as well as along the southeastern and mid-Atlantic coastal areas. This is in sharp contrast to the entire mid-section of the country from the Canadian border south to central Texas which had much below average temperatures. The pattern of warmth and cold in the contiguous U.S. in October broadly corresponded with the mean 500mb height and anomalies chart. This shows that well below normal 500mb heights existed across the upper Midwest/ northern Great Plains, which was associated with the much lower than average temperatures in October.
It was the first October in four years that temperatures in Alaska were well above normal (more than 7�F) relative to the period 1971-2000. This was a reflection of the much above average 500mb height anomalies over the state of Alaska extending well down the west coast of Canada. It was the warmest October in Alaska since 1938, and it is only the 8th time on record that Anchorage has had no snow in October. (See the October North America snow summary page for further details)
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Temperature Departures
The map to the right, based on over 500 airport stations, shows departures from the 1971-2000 normal temperatures for October 2002. Some of the largest widespread negative departures (greater than 7.5�F [4.2�C]) occurred in the Upper Mississippi Valley and Northern Great Plains. A new cold temperature record was set in Williston, ND on October 30th with a low of -9�F, breaking the old record of -3�F set in 1895 and equalled in 1991. A new record low maximum daily temperature was also recorded in Denver at 18�F on the 30th, and Marquette, Michigan had its coldest October on record with an average of only 37.9�F. This just falls below the previous record of 38�F set in 1988. See NCDC's Monthly Extremes web-page for more records.
Widespread positive temperature anomalies were limited to the southeastern quadrant of the country and the Gulf Coast. An animated map of daily temperature anomalies shows temperature variability throughout the month of October.
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August-October 2002
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The graph to the left shows mean temperature averaged across the contiguous United States based on long-term data from the U.S. Historical Climatology Network (USHCN). The value for August-October 2002 is estimated from preliminary Climate Division data using the first difference approach. August-October 2002 ranked as the 36th warmest such period in the 1895 to present record. The preliminary nationally averaged temperature for August-October 2002 was 64.6� F (18.1� C) which was 0.3� F (0.2� C) above the long-term mean.
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Despite the cooler than average October in many states, statewide mean temperatures for the August-October period were warmer than average in the east and the Southwest with 5 eastern states (New Hampshire, Rhode Island, New Jersey, Vermont and Florida) having much above average temperatures for the 3 months. A further 23 states have significantly above average temperatures.
Significantly below average statewide mean temperatures occurred in 10 states with Montana average temperatures falling into the much below average category.
When broken down by climate division (see map to the right), there are scattered divisions which were significantly warmer than average during this period in most eastern states althouth no record warm or cold divisional temperatures averaged over the August-October period occurred.
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January-October 2002 (year-to-date)
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The graph to the left shows mean temperature averaged across the contiguous United States based on long-term data from the U.S. Historical Climatology Network (USHCN). The value for January-October 2002 is estimated from preliminary Climate Division data using the first difference approach. January-October 2002 ranked as the 14th warmest such period in the 1895 to present record. The preliminary nationally averaged temperature for January-October 2002 was 56.8� F (13.8� C) which was 1.1� F (0.6� C) above the long-term mean.
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Statewide mean temperature for the January-October period was much above average for 18 states, with
Delaware having its record warmest January-October in 108 years. Connecticut, New Jersey and Maryland all had their second warmest January-October on record.
Significantly above average statewide mean temperatures also occurred in 22 out of the remaining 30 contiguous states with only Montana averaging below normal temperatures for the year-to-date. Seven states had near average temperatures for January-October. When broken down by climate division, divisions in Maryland, Virginia, Delaware, New York, and Massachusetts reached record warmth for the January-October period, while cooler than average divisional temperatures were limited to Montana, Idaho and one division each in Wyoming, South Dakota, Texas, Oklahoma and Arkansas.
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National Temperatures - November 2001-October 2002
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The graph to the left shows mean temperature averaged across the contiguous United States based on long-term data from the U.S. Historical Climatology Network (USHCN). November 2001-October 2002 ranked as the 4th warmest such period in the 1895 to present record. The preliminary nationally averaged temperature was 54.4�F (12.4�C) which was 1.6�F (0.9�C) above the long-term mean.
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Record warmth occurred in six states (RI, CT, NJ, DE, MD and OH) averaged over the last twelve months. The pattern of state-averaged monthly temperature can be seen in the map to the right. Twenty-one other states ranked in the top ten warmest such periods. Only three states had near-average temperatures for November-October (MT, ID and WY).
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Questions?
For all climate questions other than questions concerning this report, please contact the National Climatic Data Center's Climate Services Division:
Climate Services Division NOAA/National Climatic Data Center 151 Patton Avenue Asheville, NC 28801-5001 fax: 828-271-4876 phone: 828-271-4800 email: questions@ncdc.noaa.gov
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For further information on the historical climate perspective presented in this report, contact:
Catherine Godfrey NOAA/National Climatic Data Center 151 Patton Avenue Asheville, NC 28801-5001 fax: 828-271-4328 email: Catherine.S.Godfrey@noaa.gov
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Jay Lawrimore NOAA/National Climatic Data Center 151 Patton Avenue Asheville, NC 28801-5001 fax: 828-271-4328 email: Jay.Lawrimore@noaa.gov
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NCDC / Climate Monitoring / Climate of 2002 / October / U.S. Temp. / Search / Help
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