December 2007 Global Climate Report

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.

Introduction

Temperature anomalies for December 2007 are shown on the dot maps below. The dot map, below left, provides a spatial representation of anomalies calculated from the Global Historical Climatology Network (GHCN) data set of land surface stations using a 1961-1990 base period. The dot map, below right, is a product of a merged land surface and sea surface temperature anomaly analysis developed by Smith and Reynolds (2005). Temperature anomalies with respect to the 1961-1990 mean for land and ocean are analyzed separately and then merged to form the global analysis. Additional information on this product is available.

Throughout the year, anomalously warm temperatures have covered much of the globe. The January-December 2007 map of temperature anomalies shows the presence of warmer-than-average temperatures across all land areas, with the exception of the western and southern countries in South America. Warmer-than-average Sea Surface Temperatures (SSTs) occurred in the Atlantic, Indian, and the Northwest Pacific oceans. Cooler-than-average conditions were observed in the Niño 1+2 and 3 regions, the northeastern Pacific and some areas in the southern oceans.

During December, there were above average temperatures across Mexico, Alaska, Scandinavia, Argentina, most of the eastern and western states of the contiguous U.S., and most of Asia. Cooler-than-average conditions occurred in central Europe, western Australia and parts of the east coast, the Middle Eastern region, the western countries of South America, and much of the central contiguous U.S. Meanwhile, SST anomalies in the Niño 3.4 region continued to decrease in December, indicating the strengthening of an ENSO cold event (La Niña). Please see the latest ENSO discussion for additional information.

December's Land Surface Temperature
Anomalies in degrees Celsius

December's Blended Land and Sea Surface
Temperature Anomalies in degrees Celsius

The mean position of the upper level ridges of high pressure and troughs of low pressure (depicted by positive and negative 500-millibar height anomalies on the December 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.

Images of sea surface temperature conditions are available for all weeks during 2007 at the weekly SST page.

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Temperature Rankings and Graphics

Current Month / Year-to-date

Effective with the February 2006 report, NCDC transitioned from the use of the Operational Global Surface Temperature Index (Quayle et al. 1999) to the blended land and ocean dataset developed by Smith and Reynolds (2005). The differences between the two methods are discussed in Smith et al. (2005).

December 2007 ranked as the thirteenth warmest December since records began in 1880 for combined global land and ocean surface temperatures. The December land surface temperature ranked eighth warmest on record, while the ocean surface temperature ranked eighteenth warmest in the 127-year record. The global surface temperature for the combined January-December period was the fifth warmest year on record, while the global land surface temperature ranked warmest on record for the year.

December's Global Land and Ocean plot

December's Global Hemisphere plot

January-December Global Land and Ocean plot

January-December Global Hemisphere plot

The most current data may be accessed via the Global Surface Temperature Anomalies page.

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Precipitation

The maps below represent anomaly values based on the GHCN data set of land surface stations using a base period of 1961-1990. During December 2007, above average precipitation fell over areas that include the midwestern and eastern states of the contiguous U.S. and parts of South America and Australia. Drier-than-average conditions were observed in the south central states of the contiguous U.S, Uruguay, eastern Argentina, parts of Europe and India. Additional details on flooding and drought can also be found on the December Global Hazards page.

December's Precipitation Anomalies in Millimeters

December's Precipitation Percent Departures

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ENSO SST Analysis

Click here for animated loop

Sea Surface Temperature (SST) anomalies continued to decrease across the eastern and central equatorial Pacific during December with cooler anomalies extending further east of the International Date Line. Meanwhile, warmer-than-normal anomalies were observed in the far western equatorial Pacific. These conditions are indicative of a strengthening ENSO cold event (shown in the adjacent animation of weekly SST anomalies). A comprehensive summary of December 2007 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 weeks since 2003 at the weekly SST page.

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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.

Quayle, R.G., T.C. Peterson, A.N. Basist, and C. S. Godfrey, 1999: An operational near-real-time global temperature index. Geophys. Res. Lett., 26, 333-335.

Smith, T.M., and R.W. Reynolds (2005), A global merged land air and sea surface temperature reconstruction based on historical observations (1880-1997), J. Clim., 18, 2021-2036.

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