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.
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| The global mean
temperature for September through November, 1999, was well above
the long-term average, based on preliminary data. In fact, for
nearly season since the late 1970's , the global mean combined land
and ocean temperature has been above the long-term (1880-1998)
mean. Even so, this 3-month global mean temperature was
considerably cooler than the record warmth experienced in September
through November of 1997, largely due to cooler sea surface
temperatures this year. See the Global
Analysis and Global Regional
Analysis pages for more details on the global climate. |
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For the three-month
period September through November 1999, the mean temperature for
the contiguous U.S. was well above the long-term average, based
upon preliminary data. The line graph shows departures from the
1895-1998 mean. The smoothed curved line is a nine-point binomial
filter which shows the decadal-scale variations. |
| Based on preliminary
data, average total precipitation for the contiguous U.S. for the
period September through November 1999 was well below the long-term
average, falling below the long-term average for the first time in
8 years. This line graph shows departures from the 1895-1998 mean.
The smoothed curved line is a nine-point binomial filter which
shows the decadal-scale variations. See the U.S. National Analysis and U.S. Regional / Statewide Analyses pages for
more details on the U.S. climate. |
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 Extreme Events
During the September-November 1999 period, several
areas of the world experienced extremes in climate. The worst
disaster in terms of human misery was the two typhoons that struck
Eastern India and Bangladesh in October. New reports estimate that
10,000 people died in that tragedy. Elsewhere around the globe,
drought, heatwaves and floods took their toll on various areas.
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