The Summer of 2006 - It was HOT!!!

Link: National Climatic Data Center - Climate of Summer 2006

Based on preliminary data, globally averaged combined land and sea surface temperature was fourth warmest on record for August and third warmest on record for boreal summer (June - August 2006).     * June - August temperatures were above average in much of North America, Europe and Asia. There were no notable areas of colder than average conditions.     * Precipitation during June - August was above average in the U.S. Northeast, southern Argentina, and east Asia, with drier than average conditions in the U.S. Pacific Northwest, western Australia, and Scandinavia.     * ENSO conditions remained neutral during August.

Introduction

Temperature anomalies for June - August and August 2006 are shown on the dot maps below. The dot maps, below left, provide 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 maps, below right, are products of a merged land surface and sea surface temperature anomaly analysis, which is based on data from the GHCN of land temperatures and the Comprehensive Ocean-Atmosphere Data Set (COADS) of Sea-Surface Temperature (SST) data. 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. 

During boreal summer, temperatures were above average across the entire globe. There were no notable areas of cooler than average temperatures.

During boreal summer, warmer than average SSTs occurred over the North Atlantic and South Pacific. Cooler than average conditions were observed in the North Pacific and Southern Indian Oceans.Please see the latest  ENSO discussion for further information.

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During August, there were above average temperatures across much of the United States, Brazil, Scandinavia, the Middle East and Asia. Cooler than average temperatures were observed primarily in Russia, Alaska and the U.S. far Northeast. During January-August 2006, there were above average temperatures in the majority of North America, China, western Europe, South America and Africa. Cooler than average temperatures were observed in Alaska and western Australia. In January-August, warmer than average SSTs occurred in the South Pacific, North and South Atlantic and southern Indian Oceans, with cooler than average conditions observed in the North Pacific and off the coast of western Australia. In August, warmer than average SSTs occurred in the North Atlantic and the Niño 1+2 region, with cooler than average conditions observed in the North Pacific and southern Indian Oceans. Please see the latest ENSO discussion for further information.

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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 June - August 2006 map and the August 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 2006 at the weekly SST page.

Temperature Rankings and Graphics

Effective with the January, 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.

Current Month / Seasonal / Year-to-date

August	Anomaly	Rank	Warmest Year on Record
Global Land Ocean Land and Ocean	+0.73°C (+1.31°F) +0.47°C (+0.85°F) +0.54°C (+0.97°F)	3rd warmest 5th warmest 4th warmest	1998 (+0.92°C/1.66°F) 1998 (+0.54°C/0.97°F) 1998 (+0.64°C/1.15°F)
Northern Hemisphere Land Ocean Land and Ocean	+0.74°C (+1.33°F) +0.59°C (+1.06°F) +0.64°C (+1.15°F)	4th warmest 4th warmest 3rd warmest	1998 (+0.95°C/1.71°F) 2005 (+0.65°C/1.17°F) 2003 (+0.72°C/1.30°F)
Southern Hemisphere Land Ocean Land and Ocean	+0.69°C (+1.24°F) +0.38°C (+0.68°F) +0.43°C (+0.77°F)	13th warmest 7th warmest 7th warmest	1981 (+1.31°C/2.36°F) 1998 (+0.51°C/0.92°F) 1998 (+0.57°C/1.03°F)

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June-August	Anomaly	Rank	Warmest Year on Record
Global Land Ocean Land and Ocean	+0.82°C (+1.48°F) +0.46°C (+0.83°F) +0.56°C (+1.01°F)	3rd warmest 5th warmest 3rd warmest	1998 (+0.90°C/1.62°F) 1998 (+0.54°C/0.97°F) 1998 (+0.64°C/1.15°F)
Northern Hemisphere Land Ocean Land and Ocean	+0.87°C (+1.57°F) +0.54°C (+0.97°F) +0.66°C (+1.19°F)	2nd warmest 5th warmest 3rd warmest	1998 (+0.92°C/1.66°F) 2005 (+0.64°C/1.15°F) 2005 (+0.71°C/1.28°F)
Southern Hemisphere Land Ocean Land and Ocean	+0.68°C (+1.22°F) +0.40°C (+0.72°F) +0.44°C (+0.79°F)	4th warmest 7th warmest 4th warmest	2005 (+0.89°C/1.60°F) 1998 (+0.53°C/0.95°F) 1998 (+0.58°C/1.04°F)

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January-August	Anomaly	Rank	Warmest Year on Record
Global Land Ocean Land and Ocean	+0.72°C (+1.30°F) +0.43°C (+0.77°F) +0.50°C (+0.90°F)	6th warmest 6th warmest 6th warmest	2002 (+1.00°C/1.80°F) 1998 (+0.53°C/0.95°F) 1998 (+0.65°C/1.17°F)
Northern Hemisphere Land Ocean Land and Ocean	+0.80°C (+1.44°F) +0.43°C (+0.77°F) +0.57°C (+1.03°F)	7th warmest 5th warmest 5th warmest	2002 (+1.14°C/2.05°F) 2005 (+0.54°C/0.97°F) 2005 (+0.69°C/1.24°F)
Southern Hemisphere Land Ocean Land and Ocean	+0.46°C (+0.83°F) +0.43°C (+0.77°F) +0.43°C (+0.77°F)	8th warmest 5th warmest 6th warmest	2005 (+0.89°C/1.60°F) 1998 (+0.55°C/0.99°F) 1998 (+0.60°C/1.08°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. During June - August 2006, above average precipitation fell over areas that include the U.S. Northeast and Gulf Coast, Alaska, southern Argentina, eastern Europe, parts of India and southeast Asia. Heavy rain and flooding occurred in Ethiopia, India, the Phillipines and Thailand. Below average precipitation was observed in areas including the U.S./Canadian border, western Europe, Scandinavia, and western Australia. Additional details on flooding and drought can also be found on the August Global Hazards page.  During August, above average precipitation fell over areas that include the U.S. Great Plains, southern Alaska, eastern Europe and parts of India. Below average precipitation was observed across Scandinavia, parts of the U.S. southern Plains, most of Australia, and much of southeast Asia.

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ENSO SST Analysis Click here for animated loop

Sea Surface Temperatures increased across most of the central and eastern equatorial Pacific Ocean during August, but ENSO remained in a neutral state (shown in the adjacent animation of weekly sea surface temperature anomalies). A comprehensive summary of August 2006 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 during 2006 at the weekly SST page

Northern Hemisphere Sea Ice Extent

Northern Hemisphere sea ice extent, which is measured from passive microwave instruments onboard NOAA satellites, was around 6 million square kilometers as of September 5, 2006, (image to the right). According to the National Snow and Ice Data Center, during August the pattern of unusually warm conditions that have been present throughout this year were broken. Temperatures near the pole were 1° to 2°C cooler than average, inhibitng further melting this month. For further information on Northern Hemisphere snow and ice conditions, please see the NSIDC News page, provided by the NOAA's National Snow and Ice Data Center (NSIDC).

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Troposphere Current Month / Seasonal Mid-tropospheric and lower stratospheric temperature data are collected by NOAA's TIROS-N polar-orbiting satellites and adjusted for time-dependent biases by the Global Hydrology and Climate Center at the University of Alabama in Huntsville (UAH).  An independent analysis is also performed by Remote Sensing Systems (RSS) and a third analysis has been performed by Dr. Qiang Fu of the the University of Washington (UW) (Fu et al. 2004)**  to remove the influence of the stratosphere on the mid-troposphere value. The table below summarizes mid-tropospheric conditions for August 2006. These temperatures are for the atmospheric layer centered in the mid-troposphere (approximately 2-6 miles above the Earth's surface) which also includes a portion of the lower stratosphere. (The MSU channel used to measure mid-tropospheric temperatures receives about 25 percent of its signal above 6 miles). For additional information on MSU data used in this report, please see the Microwave Sounding Unit page. All datasets indicate August temperatures were above average. Records began in 1979.

August	Anomaly	Rank	Warmest Year on Record	Trend
UAH mid-trop	+0.07°C/0.13°F	12th warmest	1998 (+0.44°C/0.79°F)	+0.06°C/decade
*RSS mid-trop	+0.29°C/0.52°F	4th warmest	1998 (+0.52°C/0.94°F)	+0.14°C/decade
**UW-UAH mid-trop	+0.19°C/0.34°F	5th warmest	1998 (+0.59°C/1.06°F)	+0.11°C/decade
**UW-*RSS mid-trop	+0.38°C/0.68°F	4th warmest	1998 (+0.65°C/1.17°F)	+0.19°C/decade

*Version 02_1

June- August	Anomaly	Rank	Warmest Year on Record	Trend
UAH mid-trop	+0.07°C/0.13°F	10th warmest	1998 (+0.47°C/0.85°F)	+0.05°C/decade
*RSS mid-trop	+0.28°C/0.50°F	3rd warmest	1998 (+0.55°C/0.99°F)	+0.13°C/decade
**UW-UAH mid-trop	+0.16°C/0.29°F	7th warmest	1998 (+0.60°C/1.08°F)	+0.11°C/decade
**UW-*RSS mid-trop	+0.37°C/0.67°F	3rd warmest	1998 (+0.66°C/1.19°F)	+0.18°C/decade

*Version 02_1

Stratosphere Current Month / Seasonal The table below summarizes stratospheric conditions for August 2006. On average, the stratosphere is located approximately between 10-14 miles above the Earth's surface. Over the last decade, stratospheric temperatures have been below average in large part due to the depletion of ozone. The large increase in temperature in 1982 was caused by the volcanic eruption of El Chichon in Mexico, and the increase in 1991 was a result of the eruption of Mt. Pinatubo in the Philippines. Therefore the base period used is 1984-1990 which was chosen to avoid contamination by these eruptions.

August	Anomaly	Rank	Coolest Year on Record
UAH stratosphere	-0.48°C (-0.86°F)	5th coolest	1996 (-0.70°C/-1.26°F)
*RSS stratosphere	-0.29°C (-0.52°F)	10th coolest	1996 (-0.64°C/-1.15°F)

*Version 02_1

June-August	Anomaly	Rank	Coolest Year on Record
UAH stratosphere	-0.45°C (-0.81°F)	6th coolest	1996 (-0.73°C/-1.31°F)
*RSS stratosphere	-0.27°C (-0.49°F)	9th coolest	1996 (-0.63°C/-1.13°F)

*Version 02_1

For additional details on precipitation and temperatures in August, see the Global Hazards page.

References Christy, John R., R.W. Spencer, and W.D. Braswell, 2000: MSU Tropospheric Temperatures: Dataset Construction and Radiosonde Comparisons.   J. of Atmos. and Oceanic Technology 17  1153-1170. Fu, Q., C.M. Johanson, S.G. Warren, and D.J. Seidel, 2004: Contribution of stratospheric cooling to satellite-inferred tropospheric temperature trends. Nature, 429, 55-58. Mears, Carl A., M.C. Schabel, F.J. Wentz, 2003: A Reanalysis of the MSU Channel 2 Tropospheric Temperature Record.  J. Clim 16, 3650-3664. 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.

For all climate questions other than questions concerning this report, please contact the National Climatic Data Center's Climate Services Division:   Climate Services Division NOAA/National Climatic Data Center 151 Patton Avenue, Room 010 Asheville, NC 28801-5001 fax: 828-271-4876 phone: 828-271-4800 email: ncdc.orders@noaa.gov For questions about this report, please contact:   Jay Lawrimore NOAA/National Climatic Data Center 151 Patton Avenue Asheville, NC 28801-5001 fax: 828-271-4328 email: Jay.Lawrimore@noaa.gov -or- David Easterling NOAA/National Climatic Data Center 151 Patton Avenue Asheville, NC 28801-5001 fax: 828-271-4328 email: David.Easterling@noaa.gov