Use the form below to access monthly reports.
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.
Please Note: Effective with the July 2009 State of the Climate Report, NCDC transitioned to the new version (version 3b) of the extended reconstructed sea surface temperature (ERSST) dataset. ERSST.v3b is an improved extended SST reconstruction over version 2. Most of the improvements are justified by testing with simulated data. The primary difference in version 3b, compared to version 2, is improved low-frequency tuning that increases the sensitivity to data prior to 1930. In ERSST v3b, satellite data was removed from the ERSST product. The addition of satellite data from 1985 to present caused problems for many users. Although the satellite data were corrected with respect to the in situ data, a small residual cold bias remained at high southern latitudes where in situ data were sparse. For more information about the differences between ERSST.v3b and ERSST.v2 please read Summary of Recent Changes in the Land-Ocean Temperature Analyses and Improvements to NOAA's Historical Merged Land-Ocean Surface Temperature Analysis (1880-2006) paper.
Temperature anomalies for August 2009 and June-August 2009 are shown on the dot maps below. The dot maps on the left provide a spatial representation of anomalies calculated from the Global Historical Climatology Network (GHCN) dataset of land surface stations using a 1961-1990 base period. The dot maps on the right are a product of a merged land surface and sea surface temperature (SST) anomaly analysis developed by Smith et al. (2008). Temperature anomalies with respect to the 1961-1990 average for land and ocean are analyzed separately and then merged to form the global analysis.
The combined global land and ocean surface temperatures for August 2009 ranked as the second warmest August on record since records began in 1880. The combined global land and ocean temperature anomaly was 0.62°C (1.12°F), falling only 0.05°C (0.09°F) short of tying the record set in 1998. Sea surface temperatures (SST) during August 2009 were warmer than average across much of the world's oceans, with cooler-than-average conditions across the higher-latitude southern oceans and the northern parts of the Pacific and Atlantic oceans. The August 2009 worldwide ocean SST ranked as the warmest on record for a third consecutive month—0.57°C (1.03°F) above the 20th century average of 15.6°C (60.1°F). This broke the previous August record set in 1998, 2003, and 2005.
Meanwhile, the worldwide land surface temperature represented the fourth warmest August on record. During the month of August, warmer-than-average temperatures were present across large portions of the world's land areas with the exception of cooler-than-average conditions across Japan, the central contiguous United States, parts of Canada, western Alaska, and western Russia.
In the Southern Hemisphere, both the August 2009 average temperature for land areas, and the Hemisphere as a whole (land and ocean surface combined), represented the warmest August on record.
According to the Australian Bureau of Meteorology (BoM), Australia had its warmest August since national temperature records began 60 years ago. Temperatures ranged from 2-6°C (4-11°F) above average across the nation. The August 2009 average temperature for the nation as a whole was 2.47°C (4.45°F) above the 1961-1990 average, shattering the previous record by 0.98°C (1.76°F). In addition to the Australian mean temperature record, Australia's maximum temperature anomaly for August 2009 was 3.20°C (5.76°F), surpassing the previous record of 3.11°C (5.60°F) set in April 2005. Additionally, the maximum temperatures for all of Australia's states (with the exception of Tasmania) ranked in the top five, with Queensland and the Northern Territory having their highest August maximum temperatures.
According to the New Zealand's National Institute of Water and Atmospheric Research (NIWA), New Zealand experienced anomalously warm conditions during August 2009, resulting in the warmest August since national records began 155 years ago. The national average temperature of 10.2°C (50.4°F) was 1.7°C (3.1°F) above the August average. It was reported that the highest temperature recorded during August 2009 was 25.5°C (77.9°F), observed at Henderson (Auckland) on August 11th.
A weak El Niño persisted across the equatorial Pacific Ocean during August 2009. Consequently, sea surface temperatures across the equatorial Pacific Ocean were between 0.7-1.0°C (1.3-1.8°F) above average during the month. If El Niño continues to mature as projected by NOAA, global temperatures are likely to continue to threaten previous record highs. Please see the August 2009 ENSO discussion for additional information.
The combined global land and ocean surface temperature during June-August 2009 was the third warmest on record, behind 1998 and 2005. During the season, warmer-than-average temperatures engulfed much of the planet's surface, with the exception of cooler-than-average conditions across most of the northern contiguous U.S., the southern oceans, northern Atlantic Ocean, and parts of Canada, southeastern South America, and central and eastern Asia. The seasonal temperature for the worldwide ocean surface ranked as the warmest on record—0.58°C (1.04°F) above the 20th century average.
According to the Australian Bureau of Meteorology (BoM), the austral winter (June-August) was anomalously warm. The national average during the season was 1.33°C (2.39°F) above the 1961-1990 average. This was 0.01°C (0.02°F) shy of the record set in 1996. However, New South Wales, Victoria, and South Australia set new state seasonal mean temperatures.
The January-August 2009 map of temperature anomalies shows the presence of warmer-than-average conditions across much of the globe's surface area, with the exception of cooler-than-average conditions across Canada, parts of the northern contiguous United States, the southern oceans, and along the eastern North Pacific Ocean. The combined global land and ocean surface temperature for the year-to-date period tied with 2003 as the fifth warmest January-August period on record. This value is 0.55°C (0.99°F) above the 20th century average.
The average 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 August 2009 map and
June-August 2009, respectively) are generally reflected by areas of positive and negative temperature anomalies at the surface, respectively. For other Global products, please see the Climate Monitoring Global Products page.
Images of sea surface temperature conditions are available for all weeks during 2009 from the weekly SST page.
Current Month | Seasonal | Year-to-date
| August | Anomaly | Rank (out of 130 years) |
Warmest/Next Warmest Year on Record |
|---|---|---|---|
| Global | |||
| Land | +0.74°C (+1.33°F) | 4th warmest | 1998 (+0.95°C/1.71°F) |
| Ocean | +0.57°C (+1.03°F) | 1st warmest | 2005 (+0.56°C/1.01°F) |
| Land and Ocean | +0.62°C (+1.12°F) | 2nd warmest | 1998 (+0.67°C/1.21°F) |
| Northern Hemisphere | |||
| Land | +0.61°C (+1.10°F) | 10th warmest | 1998 (+0.96°C/1.73°F) |
| Ocean | +0.61°C (+1.10°F) | 3rd warmest | 2005 (+0.64°C/1.15°F) |
| Land and Ocean | +0.61°C (+1.10°F) | 6th warmest | 2003 (+0.72°C/1.30°F) |
| Southern Hemisphere | |||
| Land | +1.11°C (+2.00°F) | 1st warmest | 1998 (+0.90°C/1.62°F) |
| Ocean | +0.56°C (+1.01°F) | 2nd warmest | 1998 (+0.57°C/1.03°F) |
| Land and Ocean | +0.64°C (+1.15°F) | 1st warmest | 1998 (+0.62°C/1.12°F) |
| June - August | Anomaly | Rank (out of 130 years) |
Warmest/Next Warmest Year on Record |
|---|---|---|---|
| Global | |||
| Land | +0.64°C (+1.15°F) | 8th warmest | 1998 (+0.92°C/1.66°F) |
| Ocean | +0.58°C (+1.04°F) | 1st warmest | 1998 (+0.57°C/1.03°F) |
| Land and Ocean | +0.59°C (+1.06°F) | 3rd warmest | 1998 (+0.67°C/1.21°F) |
| Northern Hemisphere | |||
| Land | +0.60°C (+1.08°F) | 10th warmest | 1998 (+0.94°C/1.69°F) |
| Ocean | +0.62°C (+1.12°F) | 2nd warmest | 2005 (+0.63°C/1.13°F) |
| Land and Ocean | +0.61°C (+1.10°F) | 4th warmest | 2005 (+0.70°C/1.26°F) |
| Southern Hemisphere | |||
| Land | +0.76°C (+1.37°F) | 3rd warmest | 1998 (+0.88°C/1.58°F) |
| Ocean | +0.55°C (+0.99°F) | 2nd warmest | 1998 (+0.59°C/1.06°F) |
| Land and Ocean | +0.58°C (+1.04°F) | 2nd warmest | 1998 (+0.64°C/1.15°F) |
| January - August | Anomaly | Rank (out of 130 years) |
Warmest Year on Record |
|---|---|---|---|
| Global | |||
| Land | +0.78°C (+1.40°F) | 5th warmest | 2007 (+1.02°C/1.84°F) |
| Ocean | +0.46°C (+0.83°F) | 6th warmest | 1998 (+0.56°C/1.01°F) |
| Land and Ocean | +0.55°C (+0.99°F) | 5th warmest | 1998 (+0.67°C/1.21°F) |
| Northern Hemisphere | |||
| Land | +0.82°C (+1.48°F) | 9th warmest | 2007 (+1.22°C/2.20°F) |
| Ocean | +0.45°C (+0.81°F) | 5th warmest | 2005 (+0.54°C/0.97°F) |
| Land and Ocean | +0.59°C (+1.06°F) | 6th warmest | 2007 (+0.73°C/1.31°F) |
| Southern Hemisphere | |||
| Land | +0.68°C (+1.22°F) | 3rd warmest | 2005 (+0.86°C/1.55°F) |
| Ocean | +0.49°C (+0.88°F) | 4th warmest | 1998 (+0.60°C/1.08°F) |
| Land and Ocean | +0.51°C (+0.92°F) | 5th warmest | 1998 (+0.63°C/1.13°F) |
The most current data may be accessed via the Global Surface Temperature Anomalies page.
The maps below represent anomaly values based on the GHCN dataset of land surface stations using a base period of 1961-1990. The areas with the wettest anomalies during boreal summer (June-August) included the British Isles, northeastern contiguous U.S., southern Brazil, and parts of eastern Asia and Europe. The driest anomalies during June-August 2009 were observed across the southern U.S., northern South America, the western Pacific Islands, and most of India and southeastern Asia.
During August 2009, above-average precipitation fell over areas that included the British Isles, Alaska's panhandle, southern Brazil, southern Chile, and across parts of eastern Asia. Drier-than-average conditions were present across northern South America, eastern Australia, most of eastern Asia, India, and parts of Europe.
Australia as a whole experienced 44 percent below-average (12th lowest based on 110 years of record keeping) rainfall during August 2009. The state of Queensland and New South Wales had their fourth (93 percent below average) and eighth (74 percent below average) driest August on record, respectively. Conversely, Tasmania had its third wettest (99 percent above average) August on record. During the austral winter, the nation had 25 percent below-average rainfall—27th lowest on record. In contrast, Tasmania experienced its fourth wettest June-August on record (BoM).
Across the United Kingdom, precipitation was 133 percent of average. During August 2009, western Scotland received over twice its average August rainfall. It tied with 1985 as the wettest August since national records began in 1914. Dumfries and Galloway had their wettest August on record (Met Office).
Other notable precipitation extremes during August 2009 include the rainfall deficit across India. Over 40 percent of the country's districts were affected by drought. Hundreds of locals were forced to evacuate the affected region in search of food. Overall, the drought impacted nearly 700 million people. Mexico was in the midst of its worst drought in 70 years, affecting about 3.5 million farmers.
Additional details on flooding and drought can also be found on the August 2009 Global Hazards page.
Sea surface temperatures remained above average across the equatorial Pacific Ocean during August 2009, with SSTs more than 0.7°C (1.3°F) above average in all four Niño regions. The June-August Oceanic Niño Index was +0.7°C (1.3°F), which is above the NOAA El Niño threshold of +0.5°C (+0.9°F). These conditions are indicative of a weak El Niño. A comprehensive summary of August 2009 ENSO conditions can be found on the ENSO monitoring page. For the latest advisory on ENSO conditions, please visit NOAA's Climate Prediction Center (CPC) and the CPC ENSO Diagnostic Discussion.
Images of weekly sea surface temperature conditions are available at the weekly SST page.
According to the National Snow and Ice Data Center (NSIDC), the August 2009 Northern Hemisphere sea ice extent—which is measured from passive microwave instruments onboard NOAA satellites—was 6.26 million square kilometers (18.4 percent or 1.4 million square kilometers below the 1979–2000 average), resulting in the third lowest August sea ice extent on record, behind 2007 and 2008. When compared to August 2007—the record low—2009 was 900,000 square kilometers above the record low. This was the 13th consecutive August with sea ice extent below average. August 1996 was the last year that had above-average sea extent. August Arctic sea ice extent has decreased at an average rate of 8.7 percent per decade since 1979.
Meanwhile, the August 2009 Southern Hemisphere sea ice extent was 2.7 percent above the 1979–2000 average. This was the second largest sea ice extent in August, behind 2000. August 2009 was vastly different than the previous two years where the extent was slightly below average. Southern Hemisphere sea ice extent for August has increased at an average rate of 0.4 percent per decade.
For further information on the Northern and Southern Hemisphere snow and ice conditions, please visit the NSIDC News page, provided by NOAA's National Snow and Ice Data Center (NSIDC).
Temperatures above the Earth's surface are measured within the lower troposphere, middle troposphere, and stratosphere using in-situ balloon-borne instruments (radiosondes) and polar-orbiting satellites (NOAA's TIROS-N). The radiosonde and satellite records have been adjusted to remove time-dependent biases (artificialities caused by changes in radiosonde instruments and measurement practices as well as changes in satellite instruments and orbital features through time). Global averages from radiosonde data are available from 1958 to present, while satellite measurements date back to 1979.
Current Month | Seasonal | Year-to-date
These temperatures are for the lowest 8 km (5 miles) of the atmosphere. Information on the University of Alabama in Huntsville (UAH) and Remote Sensing Systems (RSS) sources of troposphere data is available.
| August | Anomaly | Rank (out of 31 years) |
Warmest Year on Record | Trend |
|---|---|---|---|---|
| UAH low-trop | +0.23°C/+0.41°F | 7th warmest | 1998 (+0.51°C/+0.92°F) | +0.11°C/decade |
| *RSS low-trop | +0.27°C/+0.49°F | 9th warmest | 1998 (+0.57°C/+1.03°F) | +0.16°C/decade |
*Version 03_0
| June-August | Anomaly | Rank (out of 31 years) |
Warmest Year on Record | Trend |
|---|---|---|---|---|
| UAH low-trop | +0.22°C/+0.40°F | 6th warmest | 1998 (+0.53°C/+0.96°F) | +0.10°C/decade |
| *RSS low-trop | +0.25°C/+0.45°F | 7th warmest | 1998 (+0.58°C/+1.05°F) | +0.15°C/decade |
*Version 03_0
| January- August |
Anomaly | Rank (out of 31 years) |
Warmest Year on Record | Trend |
|---|---|---|---|---|
| UAH low-trop | +0.21°C/+0.38°F | 7th warmest | 1998 (+0.61°C/+1.10°F) | +0.12°C/decade |
| *RSS low-trop | +0.22°C/+0.40°F | 8th warmest | 1998 (+0.64°C/+1.15°F) | +0.15°C/decade |
*Version 03_2
Current Month / Seasonal Year-to-date
These temperatures are for the atmospheric layer centered in the mid-troposphere (approximately 3–10 km [2–6 miles] above the Earth's surface), which also includes a portion of the lower stratosphere. (The Microwave Sounding Unit [MSU] channel used to measure mid-tropospheric temperatures receives about 25 percent of its signal above 10 km [6 miles].) Because the stratosphere has cooled due to increasing greenhouse gases in the troposphere and losses of ozone in the stratosphere, the stratospheric contribution to the tropospheric average, as measured from satellites, may create an artificial component of cooling to the mid-troposphere temperatures. The University of Washington (UW) versions of the UAH and RSS analyses attempt to remove the stratospheric influence from the mid-troposphere measurements, and as a result the UW versions tend to have a larger warming trend than either the UAH or RSS versions. For additional information, please see NCDC's Microwave Sounding Unit page.
The radiosonde data used in this global analysis were developed using the Lanzante, Klein, Seidel (2003) ("LKS") bias-adjusted dataset and the First Difference Method (Free et al. 2004) (RATPAC). Additional details are available. Satellite data have been adjusted 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 University of Washington (UW) (Fu et al. 2004)** to remove the influence of the stratosphere on the mid-troposphere value. Global averages from radiosonde data are available from 1958 to present, while satellite measurements began in 1979.
Radiosonde measurements indicate that, for the January-August year-to-date period, temperatures in the mid-troposphere were 0.44°C (0.80°F) above average, resulting in the seventh warmest January-August (out of 52 years) since global radiosonde measurements began in 1958. This was the 23rd consecutive January-August period with temperature anomalies warmer than average. Meanwhile, satellite analyses of the January-August year-to-date period for the middle troposphere varied from 10th to 15th warmest in the 31-year satellite record.
Similar to January-August year-to-date, radiosonde measurements indicate that temperatures were 0.51°C (0.93°F) above average during the season, giving June-August a rank of fifth warmest on record. The table below shows that satellite measurements for the season varied from 9th to 12th warmest on record.
The global mid-troposphere temperatures were above average during August 2009. As shown in the table below, satellite measurements for August 2009 ranked seventh warmest to tenth warmest on record.
| August | Anomaly | Rank (out of 31 years) |
Warmest Year on Record | Trend |
|---|---|---|---|---|
| UAH mid-trop | +0.11°C/+0.20°F | 9th warmest | 1998 (+0.45°C/+0.81°F) | +0.05°C/decade |
| *RSS mid-trop | +0.17°C/+0.30°F | 10th warmest | 1998 (+0.50°C/+0.91°F) | +0.10°C/decade |
| **UW-UAH mid-trop | +0.20°C/+0.36°F | 7th warmest | 1998 (+0.60°C/+1.08°F) | +0.10°C/decade |
| **UW-*RSS mid-trop | +0.25°C/+0.45°F | 9th warmest | 1998 (+0.64°C/+1.15°F) | +0.15°C/decade |
*Version 03_2
| June-August | Anomaly | Rank (out of 31 years) |
Warmest Year on Record | Trend |
|---|---|---|---|---|
| UAH mid-trop | +0.06°C/+0.11°F | 12th warmest | 1998 (+0.48°C/+0.86°F) | +0.04°C/decade |
| *RSS mid-trop | +0.12°C/+0.22°F | 10th warmest | 1998 (+0.52°C/+0.94°F) | +0.09°C/decade |
| **UW-UAH mid-trop | +0.15°C/+0.27°F | 10th warmest | 1998 (+0.61°C/+1.09°F) | +0.09°C/decade |
| **UW-*RSS mid-trop | +0.20°C/+0.36°F | 9th warmest | 1998 (+0.64°C/+1.15°F) | +0.14°C/decade |
| RATPAC | +0.51°C/+0.93°F | 5th warmest | 1998 (+0.87°C/+1.57°F) | +0.15°C/decade |
*Version 03_2
| January- August |
Anomaly | Rank (out of 31 years) |
Warmest Year on Record | Trend |
|---|---|---|---|---|
| UAH mid-trop | +0.04°C/+0.07°F | 15th warmest | 1998 (+0.55°C/+0.99°F) | +0.04°C/decade |
| *RSS mid-trop | +0.09°C/+0.16°F | 13th warmest | 1998 (+0.59°C/+1.06°F) | +0.09°C/decade |
| **UW-UAH mid-trop | +0.14°C/+0.25°F | 12th warmest | 1998 (+0.68°C/+1.22°F) | +0.10°C/decade |
| **UW-*RSS mid-trop | +0.17°C/+0.31°F | 10th warmest | 1998 (+0.71°C/+1.28°F) | +0.14°C/decade |
| RATPAC | +0.44°C/+0.80°F | 7th warmest | 1998 (+0.83°C/+1.49°F) | +0.14°C/decade |
*Version 03_2
Note: RATPAC's rank is based on records that began in 1958 (52 years).
The table below summarizes stratospheric conditions for August 2009. On average, the stratosphere is located approximately 16–23 km (10–14 miles) above the Earth's surface. Over the last decade, stratospheric temperatures have been below average in part due to the depletion of ozone. The large positive anomaly in 1982 was caused by the volcanic eruption of El Chichon in Mexico, and the sharp jump in temperature in 1991 was a result of the eruption of Mt. Pinatubo in the Philippines. In both cases the temperatures returned to pre-eruption levels within two years.
| August | Anomaly | Rank (out of 31 years) |
Coolest Year on Record |
|---|---|---|---|
| UAH stratosphere | -0.44°C (-0.79°F) | 7th coolest | 1996 (-0.72°C/-1.30°F) |
| *RSS stratosphere | -0.38°C (-0.69°F) | 8th coolest | 1996 (-0.66°C/-1.18°F) |
*Version 03_2
| June-August | Anomaly | Rank (out of 31 years) |
Coolest Year on Record |
|---|---|---|---|
| UAH stratosphere | -0.49°C (-0.88°F) | 8th coolest | 1996 (-0.71°C/-1.28°F) |
| *RSS stratosphere | -0.41°C (-0.75°F) | 8th coolest | 1996 (-0.64°C/-1.15°F) |
*Version 03_2
For additional details on precipitation and temperatures in August, see the Global Hazards page.
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.
Free, M., D.J. Seidel, J.K. Angell, J. Lanzante, I. Durre and T.C. Peterson (2005) Radiosonde Atmospheric Temperature Products for Assessing Climate (RATPAC): A new dataset of large-area anomaly time series, J. Geophys. Res., 10.1029/2005JD006169.
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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.
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For questions on technical or scientific content of this report, please contact:
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CMB.Contact@noaa.govFor climate data orders, please contact the National Climatic Data Center's Climate Services and Monitoring Division:
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