Global Analysis - May 2009
Note: The data presented in this report are preliminary. Ranks and anomalies may change as more complete data are received and processed. Effective September 2012, the GHCN-M version 3.2.0 dataset of monthly mean temperature replaced the GHCN-M version 3.1.0 monthly mean temperature dataset. Beginning with the August 2012 Global monthly State of the Climate Report, released on September 17, 2012, GHCN-M version 3.2.0 is used for NCDC climate monitoring activities, including calculation of global land surface temperature anomalies and trends. For more information about this newest version, please see the GHCN-M version 3.2.0 Technical Report.
*The GHCN-M version 3.1.0 Technical Report was revised on September 5, 2012 to accurately reflect the changes incorporated in that version. Previously that report incorrectly included discussion of changes to the Pairwise Homogeneity Algorithm (PHA). Changes to the PHA are included in version 3.2.0 and described in the version 3.2.0 Technical Report. Please see the Frequently Asked Questions to learn more about this update.
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.
Please Note: Beginning with the July 2009 State of the Climate Report, NCDC will switch to a 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 May 2009 and March-May 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 and Reynolds (2005). Temperature anomalies with respect to the 1961-1990 average for land and ocean are analyzed separately and then merged to form the global analysis. Additional information on this product is available.
The May 2009 map shows warmer-than-average temperatures across much of the world's land areas, with the most anomalous warmth over Alaska, Iceland, the western contiguous U.S., and much of Europe and Asia. Meanwhile, cooler-than-average conditions were present across New Zealand, Canada, and parts of western and central Asia and Australia. Temperatures were 2-5°C (4-9°F) below the 1961-1990 average across large areas in Canada. According to Environment Canada, some locations across Ontario, Canada had their coolest mean temperature since 2002; meanwhile, the town of Kapuskasing had its coolest mean temperature since 1997 (Source: Environment Canada).
Sea surface temperatures during May 2009 were warmer than average across much of the world's oceans, with the exception of cooler-than-average conditions across parts of the northeastern Pacific, and parts of the northern and central Atlantic and Southern oceans. SST anomalies in all Niño regions continued to warm during May 2009, indicating persistence of ENSO-neutral conditions. Please see the May 2009 ENSO discussion for additional information.
During the boreal spring (March-May), temperatures were above average in Mexico, Europe, southern South America, northwestern Alaska, northwestern and southern Africa, and most of the contiguous U.S., Asia, and parts of Australia. Cooler-than-average temperatures were present across the Hawaiian Islands, Canada, and parts of the north central and northwestern United States.
The January-May 2009 map of temperature anomalies shows the presence of warmer-than-average conditions across much of the world's land areas, with the exception of cooler-than-average temperatures across parts of northeastern Australia, eastern Siberia, southern Alaska, north central contiguous U.S., and most of Canada. Sea surface temperatures were warmer than average across the North Indian and western Pacific oceans, and most of the Atlantic Ocean. Cooler-than-average SSTs were present across the equatorial Pacific Ocean, along the western coasts of North America and northwestern Africa, and across most of the southern oceans.
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 March-May 2009 map and May 2009 map, 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.
Temperature Rankings and Graphics
The combined global land and ocean surface temperature was the fourth warmest on record in May and the fifth warmest on record for boreal spring (March-May). The year-to-date (January-May) land and ocean combined temperature tied with 2003 as the sixth warmest on record. The ranks found in the tables below are based on records that began in 1880.
(out of 130 years)
Year on Record
|Land||+0.66°C (+1.19°F)||8th warmest||2005 (+0.94°C/1.69°F)|
|Ocean||+0.48°C (+0.86°F)||3rd warmest||1998 (+0.54°C/0.97°F)|
|Land and Ocean||+0.53°C (+0.95°F)||4th warmest||1998 (+0.62°C/1.12°F)|
|Land||+0.66°C (+1.19°F)||9th warmest||2001 (+1.16°C/2.09°F)|
|Ocean||+0.44°C (+0.79°F)||7th warmest||2005 (+0.60°C/1.08°F)|
|Land and Ocean||+0.52°C (+0.94°F)||9th warmest||2005 (+0.73°C/1.31°F)|
|Land||+0.65°C (+1.17°F)||7th warmest||2002 (+1.03°C/1.85°F)|
|Ocean||+0.52°C (+0.94°F)||2nd warmest||1998 (+0.58°C/1.04°F)|
|Land and Ocean||+0.54°C (+0.97°F)||3rd warmest||1998 (+0.61°C/1.10°F)|
|March - May||Anomaly||Rank
(out of 130 years)
Year on Record
|Land||+0.87°C (+1.57°F)||9th warmest||2007 (+1.16°C/2.09°F)|
|Ocean||+0.44°C (+0.79°F)||5th warmest||1998 (+0.53°C/0.95°F)|
|Land and Ocean||+0.56°C (+1.01°F)||5th warmest||2005 (+0.65°C/1.17°F)|
|Land||+0.91°C (+1.64°F)||9th warmest||2000 (+1.37°C/2.47°F)|
|Ocean||+0.38°C (+0.68°F)||8th warmest||2005 (+0.52°C/0.94°F)|
|Land and Ocean||+0.58°C (+1.04°F)||11st warmest||2005 (+0.77°C/1.39°F)|
|Land||+0.76°C (+1.37°F)||4th warmest||2005 (+0.99°C/1.78°F)|
|Ocean||+0.49°C (+0.88°F)||3rd warmest||1998 (+0.57°C/1.03°F)|
|Land and Ocean||+0.53°C (+0.95°F)||3rd warmest||1998 (+0.62°C/1.12°F)|
|January - May||Anomaly||Rank
(out of 130 years)
Year on Record
|Land||+0.90°C (+1.62°F)||6th warmest||2007 (+1.27°C/2.29°F)|
|Ocean||+0.42°C (+0.76°F)||7th warmest||1998 (+0.53°C/0.95°F)|
|Land and Ocean||+0.54°C (+0.97°F)||6th warmest||2007 (+0.65°C/1.17°F)|
|Land||+0.96°C (+1.73°F)||7th warmest||2007 (+1.46°C/2.63°F)|
|Ocean||+0.36°C (+0.65°F)||7th warmest||1998 (+0.50°C/0.90°F)|
|Land and Ocean||+0.58°C (+1.04°F)||7th warmest||2007 (+0.83°C/1.49°F)|
|Land||+0.69°C (+1.24°F)||4th warmest||2005 (+0.91°C/1.64°F)|
|Ocean||+0.47°C (+0.85°F)||4th warmest||1998 (+0.57°C/1.03°F)|
|Land and Ocean||+0.50°C (+0.90°F)||5th warmest||1998 (+0.61°C/1.10°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 spring included the eastern half of the contiguous U.S., northeastern Brazil, and southeastern Asia. The areas with the driest anomalies during March-May 2009 included South Africa, Alaska's panhandle, parts of northeastern and southern South America, eastern Asia, and most of Australia.
During May 2009, above-average precipitation fell over areas that included southeastern Asia, the southeastern contiguous U.S., northeastern Brazil, east central Australia, and parts of Russia, northern Europe, and northern India. Drier-than-average conditions were present across the Hawaiian Islands, Alaska's panhandle, the central U.S., northeastern South America, southern Europe, eastern Asia, and most of Australia.
Notable precipitation extremes during May 2009 include the heavy rain brought by typhoons Kujira and Chan-hom to parts of the Philippine Islands, prompting widespread floods and landslides. Torrential rain during the week of May 17 produced floods that claimed the lives of 11 people across Haiti. In Piaui, Brazil, heavy downpours caused a dam to rupture on May 28, inundating 120 homes and killing four people. In eastern Australia, a major storm brought heavy rain that caused significant floods in the region, forcing residents to flee the affected area. According to Australia's Bureau of Meteorology (BoM), the town of Dorrigo, New South Wales, received a total of 934 mm (37 inches) of precipitation during May 2009, including 409 mm (16 inches) that fell on May 22—the now second highest daily rainfall on record for the month of May in New South Wales (BoM).
Additional details on flooding and drought can also be found on the May 2009 Global Hazards page.
ENSO SST Analysis
As shown in the adjacent animation, SST warmed across the equatorial Pacific during May 2009, resulting in warmer anomalies in all Niño regions when compared to April 2009 anomalies. The Oceanic Niño Index (three-month [March-April-May] running average) was -0.1°C (-0.2°F), which is above the threshold of -0.5°C (-0.9°F), indicating ENSO-neutral conditions. A comprehensive summary of May 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 sea surface temperature conditions are available for all weeks since 2003 at the weekly SST page.
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.