Global Highlights:

  • Based on preliminary data, global average combined land and sea surface temperature was fifth warmest on record for December 2004
  • December temperatures were above average across Scandinavia, Japan, Alaska and the majority of the U.S., with below average temperatures over eastern Canada, the Middle East and the majority of Siberia
  • Precipitation during December was above average over the western coast of Alaska, the southwestern U.S. and Japan, with drier than average conditions in parts of Southeast Asia, the central portions of the U.S., and the majority of Europe
  • Sea Surface Temperatures (SSTs) continued to be above normal in the central equatorial Pacific
 

Contents of this Section:



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.

Top of Page Introduction

Temperature anomalies for December are shown on the two maps* below. 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 December 2004, indicating above average temperatures in Alaska, parts of West Africa, Norway, western and southern Australia, Japan and the majority of eastern Europe, with cooler than average temperatures over most of Siberia, the Middle East, Mexico, parts of Southeast Asia and the eastern half of Canada.

*The two maps below utilize different base periods and may reflect different anomaly values of land surface temperatures.
Current month's Temperature Dot map
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Current month's Temperature blended SSMI map
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Above average sea surface temperatures are also evident in the blended product, above right. Warmer than average conditions covered large parts of the central and eastern Pacific in association with weak El Niño conditions. Sea surface temperatures were also warmer than average in much of the northern Pacific.

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 December 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.



Top of PageTemperature Rankings and Graphics

Current Month / Year-to-date
December Anomaly Rank Warmest Year on Record
Global
Land
Ocean
Land and Ocean
+0.41°C (+0.74°F)
+0.50°C (+0.90°F)
+0.47°C (+0.85°F)
23rd warmest
2nd warmest
5th warmest
1939 (+1.09°C/1.96°F)
1997 (+0.62°C/1.12°F)
1997 (+0.62°C/1.12°F)
Northern Hemisphere
Land
Ocean
Land and Ocean
+0.34°C (+0.61°F)
+0.57°C (+1.03°F)
+0.48°C (+0.86°F)
32nd warmest
warmest
8th warmest
1939 (+1.61°C/2.90°F)
2nd - 1997 (+0.57°C/1.03°F)
2003 (+0.66°C/1.19°F)
Southern Hemisphere
Land
Ocean
Land and Ocean
+0.68°C (+1.22°F)
+0.40°C (+0.72°F)
+0.45°C (+0.81°F)
6th warmest
8th warmest
6th warmest
1972 (+0.79°C/1.42°F)
1997 (+0.61°C/1.10°F)
1997 (+0.64°C/1.15°F)

Global Land and Ocean Triad plot
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Global Hemisphere Triad plot
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January-December Anomaly Rank Warmest Year on Record
Global
Land
Ocean
Land and Ocean
+0.83°C (+1.50°F)
+0.42°C (+0.76°F)
+0.54°C (+0.97°F)
4th warmest
3rd warmest
4th warmest
1998 (+0.98°C/1.76°F)
1998 (+0.47°C/0.85°F)
1998 (+0.63°C/1.13°F)
Northern Hemisphere
Land
Ocean
Land and Ocean
+0.90°C (+1.62°F)
+0.50°C (+0.90°F)
+0.66°C (+1.19°F)
3rd warmest
warmest
2nd warmest
1998 (+1.03°C/1.85°F)
2nd - 1998 (+0.49°C/0.88°F)
1998 (+0.71°C/1.28°F)
Southern Hemisphere
Land
Ocean
Land and Ocean
+0.56°C (+1.01°F)
+0.37°C (+0.67°F)
+0.40°C (+0.72°F)
4th warmest
7th warmest
6th warmest
1998 (+0.77°C/1.40°F)
1998 (+0.47°C/0.85°F)
1998 (+0.53°C/0.95°F)

Global Land and Ocean Triad plot
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Global Hemisphere Triad plot
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The most current data may be accessed via the Global Surface Temperature Anomalies page.


Top of 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 December 2004, above average precipitation fell in Alaska, the southwestern U.S., South Africa, parts of Scandinavia and Italy. Below average precipitation was observed in India, the southeastern U.S., Brazil, southeastern Asia, Portugal and Turkey.
Precipitation Dot map in Millimeters
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Percent Precipitation Dot map
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The maps below were produced 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. 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. Data in these areas that are normally snow covered are displayed as missing. The SSM/I products are experimental and are under continuing review and development.

SSM/I Wetness map
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SSM/I snowcover map
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Top of Page ENSO SST Analysis




Last week of the month's ENSO condtions Map
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  • Sea Surface Temperatures (SSTs) continued to be above normal in the central equatorial Pacific during December (as shown in the adjacent animation of weekly sea surface temperature anomalies), suggesting ENSO is in a weak warm phase. A comprehensive summary of December 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

  • Images of sea surface temperature conditions are available for all months 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.


Citing This Report

NOAA National Centers for Environmental Information, Monthly Global Climate Report for December 2004, published online January 2005, retrieved on March 28, 2024 from https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/200412.