Global Analysis - September 2001

Note: The data presented in this report are preliminary. Ranks and anomalies may change as more complete data are received and processed. Effective September 2012, the GHCN-M version 3.2.0 dataset of monthly mean temperature replaced the GHCN-M version 3.1.0 monthly mean temperature dataset. Beginning with the August 2012 Global monthly State of the Climate Report, released on September 17, 2012, GHCN-M version 3.2.0 is used for NCDC climate monitoring activities, including calculation of global land surface temperature anomalies and trends. For more information about this newest version, please see the GHCN-M version 3.2.0 Technical Report.

*The GHCN-M version 3.1.0 Technical Report was revised on September 5, 2012 to accurately reflect the changes incorporated in that version. Previously that report incorrectly included discussion of changes to the Pairwise Homogeneity Algorithm (PHA). Changes to the PHA are included in version 3.2.0 and described in the version 3.2.0 Technical Report. Please see the Frequently Asked Questions to learn more about this update.

Global Highlights:

  • Global average land and sea surface temperature was the eighth warmest on record for September
  • Lower tropospheric temperatures were slightly cooler than average during the month
  • Temperatures in the lower stratosphere were cooler than average
  • Above average precipitation was most notable across the islands of the western Pacific and central Europe, with below average precipitation across most of India
  

Contents of this Section:
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Top of Page Introduction

Anomalous warmth (using a 1992-2001 base period as shown in the adjacent blended product of satellite and in-situ data) was dominant across much of Canada and the western U.S., much of northwest Russia and southeastern Australia. While strong upper level ridges of high pressure controlled the weather in these areas during September, upper level troughs of low pressure (depicted by negative 500 millibar height anomalies) were situated across central Europe and eastern Siberia. Temperature anomalies calculated from in-situ station data using a 1961-1990 base period also show the cooler than average temperatures in these regions as well as over the eastern U.S. Global Blended Temperature in September 2001
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Top of Page Temperature

  • September 2001 global land and ocean temperature ranked as eighth warmest in the 1880 to present record and was 0.33°C (0.59°F) above the long-term average (0.23°C / 0.41°F above the 1961-1990 mean)
  • Temperatures averaged across land areas were fifth warmest for September, or 0.46°C (0.83°F) above average
 Global Temp Anomalies in September 2001
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September Hemispheric Temperatures
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  • Northern Hemispheric temperatures remained above average (0.30°C / 0.54°F above the mean), although no records were in jeopardy this month
  • Temperatures averaged across the Southern Hemisphere were fourth warmest for September, or 0.40°C / 0.72°F above average using an 1880-present base period (0.25°C / 0.45°F above average using a 1961-1990 base period)
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Top of Page Precipitation

  • Several landfalling tropical storms and typhoons in the western Pacific provided locally excessive rainfall from Japan south into the northern Philippines
  • Monthly precipitation surpluses of 100-200 mm (3.94-7.87 inches) were common across parts of central Europe
  • Monsoon rains were much lighter than average across most of India
 Global Precip Anomalies in September 2001 larger image

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References:

Peterson, T.C. and R.S. Vose, 1997: An Overview of the Global Historical Climatology Network Database. Bull. Amer. Meteorol. Soc., 78, 2837-2849.

Citing This Report

NOAA National Climatic Data Center, State of the Climate: Global Analysis for September 2001, published online October 2001, retrieved on May 25, 2013 from http://www.ncdc.noaa.gov/sotc/global/2001/9.