Global Highlights:
- Based on preliminary data for September 2004, global average
combined land and sea surface temperature was fourth warmest on
record
- September temperatures were above average throughout the
northern Great Plains of the U.S., the eastern half of Canada and
Japan, with below average temperatures in Alaska, Mongolia and
western Australia
- Precipitation during September was above average across the
eastern U.S., Alaska and Southeast Asia, with drier than average
conditions in the Lower Mississippi Valley of the U.S., Brazil and
eastern Europe
- Above normal SSTs across the central and equatorial Pacific
basin suggest a weak El Niño is developing
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Contents of this Section:
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The data presented in this report are preliminary. Ranks and
anomalies may change as more complete data are received and
processed. The most current data may be accessed via the Global Surface
Temperature Anomalies page.
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Introduction
The two maps below utilize different base periods and may reflect
different anomaly values of land surface temperatures. The dot map
on the left uses anomalies that were calculated from the Global
Historical Climatology Network (GHCN) data set of land surface
stations using a 1961-1990 base period. The map on the right is a
blended product
which uses satellite and surface anomaly values of measured land
and ocean temperatures as well as SSTs with the base period of
1988-2004. Both maps reflect conditions during September 2004,
indicating above average temperatures in the upper Mississippi
Valley of the U.S., western Europe, the Middle East, Brazil and
Scandinavia, with cooler than average temperatures in Alaska, the
Pacific Northwest of the U.S., South Africa, France, Mongolia and
parts of Australia.
The mean position of upper level ridges of high pressure and
troughs of low pressure (depicted by positive and negative 500
millibar height anomalies on the September 2004
map) are generally reflected by areas of positive and negative
temperature anomalies at the surface, respectively. For other
Global products see the Climate Monitoring
Global Products page. |
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Temperature Rankings and Graphics
Current Month / Year-to-date
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September |
Anomaly |
Rank |
Warmest Year on
Record |
Global
Land
Ocean
Land and Ocean |
+0.56°C (+1.01°F)
+0.49°C (+0.88°F)
+0.51°C (+0.92°F) |
5th warmest
3rd warmest
4th warmest |
1998
(+0.75°C/1.35°F)
2003 (+0.53°C/0.95°F)
2003 (+0.57°C/1.03°F) |
Northern Hemisphere
Land
Ocean
Land and Ocean |
+0.61°C (+1.10°F)
+0.60°C (+1.08°F)
+0.61°C (+1.10°F) |
4th warmest
2nd warmest
2nd warmest |
1998
(+0.81°C/1.46°F)
2003 (+0.65°C/1.17°F)
2003 (+0.66°C/1.19°F) |
Southern Hemisphere
Land
Ocean
Land and Ocean |
+0.44°C (+0.80°F)
+0.42°C (+0.76°F)
+0.43°C (+0.77°F) |
17th warmest
7th warmest
7th warmest |
2003
(+0.75°C/1.35°F)
1997 (+0.55°C/1.00°F)
1997 (+0.58°C/1.04°F) |
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January-September |
Anomaly |
Rank |
Warmest Year on
Record |
Global
Land
Ocean
Land and Ocean |
+0.79°C (+1.42°F)
+0.39°C (+0.70°F)
+0.51°C (+0.92°F) |
5th warmest
4th warmest
4th warmest |
1998
(+1.05°C/1.90°F)
1998 (+0.50°C/0.90°F)
1998 (+0.67°C/1.21°F) |
Northern Hemisphere
Land
Ocean
Land and Ocean |
+0.88°C (+1.58°F)
+0.48°C (+0.86°F)
+0.64°C (+1.15°F) |
3rd warmest
2nd warmest
3rd warmest |
2002
(+1.15°C/2.07°F)
1998 (+0.52°C/0.94°F)
1998 (+0.75°C/1.35°F) |
Southern Hemisphere
Land
Ocean
Land and Ocean |
+0.44°C (+0.80°F)
+0.35°C (+0.63°F)
+0.37°C (+0.66°F) |
8th warmest
7th warmest
6th warmest |
1998
(+0.83°C/1.50°F)
1998 (+0.50°C/0.90°F)
1998 (+0.57°C/1.03°F) |
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The most current data may be accessed via the Global Surface
Temperature Anomalies page.
Precipitation
The maps below represent anomaly values based on the GHCN data
set of land surface stations using a base period of 1961-1990. The
map to the left is precipitation anomalies measured in millimeters,
the map to the right is the percentage of average (1961-1990)
precipitation. During September 2004, much above average
precipitation fell across the southeastern U.S., southern portions
of Alaska, the Caribbean, southeastern Asia, Sri Lanka and
Scandinavia. Below average precipitation was observed in the
southern Great Plains of the U.S., the Philippines, western parts
of Canada, eastern Europe and Brazil.
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The satellite images below were acquired from SSM/I satellite data
using a base period of 1988-2004. The map on the left reflects
surface liquid wetness conditions, while the map on the right
reflects snow cover conditions for the month. Snow covered areas
that are normally snow-free during this month will appear drier
than average on the wetness image since a wetness value cannot be
determined for regions that are snow covered. Data in these areas
that are normally snow covered are displayed as missing. This is
due to the snow crystalline structure which produces a considerable
amount of scatter and makes it difficult for the SSM/I to
accurately detect the surface conditions. The SSM/I products are
experimental and are under continuing review and development.
Additional data and information can be found on the SSM/I Browser. |
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ENSO SST Analysis
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- A consensus of indices suggests above normal SSTs in the
central and equatorial Pacific basins which suggests ENSO was in a
weak warm phase (El Niño) during September 2004 (as shown in
the adjacent animation of weekly sea surface temperature
anomalies). A comprehensive summary of September 2004 ENSO
conditions can be found on the ENSO monitoring
page. For the latest advisory on ENSO conditions go to NOAA's Climate Prediction
Center (CPC) and the CPC ENSO Diagnostic
Discussion
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- Images of sea surface temperature conditions are available for
all months to date during 2004
at the weekly SST page
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.
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NOAA's National Centers for Environmental Information
