Global Analysis - October 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 combined global land and ocean surface temperature for October 2009 was the sixth warmest on record, with an anomaly of 0.57°C (1.03°F) above the 20th century average of 14.0°C (57.1°F).
- The global land surface temperature for October 2009 was 0.82°C (1.48°F) above the 20th century average of 9.3°C (48.7°F), and ranked as the sixth warmest October on record.
- The worldwide ocean temperature was the fifth warmest October on record, with an anomaly of 0.50°C (0.90°F) above the 20th century average of 15.9°C (60.6°F).
- For the year to date, the global combined land and ocean surface temperature of 14.7 °C (58.4 °F) tied with 2007 as the fifth-warmest January-through-October period on record. This value is 0.56°C (1.01°F) above the 20th century average.
Please Note: The data presented in this report are preliminary. Ranks and anomalies may change as more complete data are received and processed. 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. For more information about the differences between ERSST.v3b and ERSST.v2 and to access the most current data, please visit NCDC's Global Surface Temperature Anomalies page.
Temperature anomalies for October 2009 are shown on the dot maps below. The dot map on the left provides 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 map on the right is a product of a merged land surface and sea surface temperature (SST) anomaly analysis developed by Smith et al. (2008). For the merged land surface and SST analysis, temperature anomalies with respect to the 1971-2000 average for land and ocean are analyzed separately and then merged to form the global analysis. For more information, please visit NCDC's Global Surface Temperature Anomalies page.
Please Note: This preliminary assessment was made before data from Canada was made available. Therefore, some of the ranks presented in this report could change slightly when Canadian data is included in the final record. The inclusion of the missing data may cause modest changes to global-scale ranks. The assessment for Northern Hemisphere land temperatures could change by several ranks.
The combined global land and ocean surface temperature anomaly for October 2009 was 0.57°C (1.03°F) above the 20th century average, resulting in the sixth warmest October on record since records began in 1880. Similar to the combined global land and ocean temperatures, the worldwide land surface temperature was the sixth warmest October on record, with a temperature anomaly of 0.82°C (1.48°F) above the 20th century average. As shown in the dot maps above, warmer-than-average temperatures during the month of October were present across much of the world's land areas. The warmest anomalies occurred in the high latitudes of the Northern Hemisphere, specifically, in Alaska and northern and eastern Russia. Cooler-than-average conditions were present across the contiguous U.S., Scandinavia, New Zealand, and parts of northern Europe, northern Australia, and southern South America.
For the contiguous U.S., the national temperature average during October 2009 was much-below average, ranking in the top five coolest such month. Temperatures were below normal in eight of the nation's nine climate regions, with five of them much-below average. Please see the United States October 2009 National Overview for additional information.
According to New Zealand's National Institute of Water and Atmospheric Research (NIWA), New Zealand experienced anomalously cool conditions during October 2009, resulting in the coolest October since 1945. The national average was 10.6°C (51.1°F), 1.4°C (2.5°F) below the long-term October average. Many locations reported record low October temperatures, with temperatures over 2.0°C (3.6°F) below average.
In contrast, Darwin, Northern Territory, Australia experienced warmer-than-average temperatures during October 2009. The capital city recorded an average maximum temperature of 34.8°C (94.6°F) on October 2009, the highest on record for any month (Source: Australia's Bureau of Meteorology).
The worldwide sea surface temperatures (SST) during October 2009 were warmer than average across all oceans, with the exception of cooler-than-average conditions across much of the near-Antarctic southern oceans, the Gulf of Alaska, and parts of northwestern Atlantic Ocean, and along the western coasts of Australia and South America. The global ocean temperature represented the fifth warmest October on record, with an anomaly of 0.50°C (0.90°F) above the 20th century average. El Niño persisted across the equatorial Pacific Ocean during October 2009. Sea surface temperature anomalies were at least 1.0°C (1.8°F) above average across much of the central and east-central equatorial Pacific Ocean. El Niño is expected to strengthen and last through the Northern Hemisphere winter 2009-2010, according to NOAA's Climate Prediction Center (CPC).
The January-October 2009 map of temperature anomalies shows the presence of warmer-than-average conditions across much of the globe's surface, with the exception of cooler-than-average conditions across parts of Canada, the northern contiguous United States, the southern oceans, and along the northeastern Pacific Ocean. The combined global land and ocean surface temperature for the year-to-date period tied with 2007 as the fifth warmest January-October period on record. This value is 0.56°C (1.01°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 October 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
(out of 130 years)
|Warmest on Record|
|Land and Ocean||+0.57||+1.03||6th warmest||2003||+0.71||+1.28|
|Land and Ocean||+0.64||+1.15||5th warmest||2003||+0.85||+1.53|
|Land and Ocean||+0.53||+0.95||5th warmest||1997||+0.61||+1.10|
*Signifies a tie
(out of 130 years)
|Warmest on Record|
|Land and Ocean||+0.56||+1.01||5th warmest*||1998||+0.63||+1.13|
|Land and Ocean||+0.61||+1.10||5th warmest*||2007||+0.71||+1.28|
|Land and Ocean||+0.51||+0.92||5th warmest||1998||+0.60||+1.08|
*Signifies a tie
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 October 2009 included the contiguous U.S., Brazil, the Philippine Islands, the southern Pacific islands, and parts of eastern Europe. The driest anomalies during October 2009 were observed across Alaska's panhandle and southern India.
Hurricane Rick, the 18th named storm for the eastern North Pacific basin in 2009, became the second-most intense North East Pacific hurricane on record, behind Linda of 1997, and the strongest hurricane to form in October since reliable records began. Rick made landfall near Mazaltan, Mexico on October 21st, producing heavy rain and causing two fatalities.
The Philippine Islands had well-above-average precipitation during October 2009. This was mainly due to the combined effects of Parma, Lupit, and Mirinae, which brought torrential rain across the islands, triggering fatal floods and wreaking havoc across the area.
Other notable precipitation extremes during October 2009 included heavy rain in Sicily, Italy. Over 200 mm (8 inches) of rain fell in a three-hour period on October 2nd. The heavy downpours triggered mudslides that claimed the lives of 20 people with 40 others missing. These were Italy's worst mudslides in over a decade. India's southern states—Karnataka and Andhra Pradesh—had their heaviest rainfall in over six decades. The effects of the copious rainfall were responsible for the deaths of 286 people and for leaving 2.5 million people homeless.
Additional details on flooding and drought can also be found on the October 2009 Global Hazards 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.
Smith, et al (2008), Improvements to NOAA's Historical Merged Land-Ocean Surface Temperature Analysis (1880-2006), J. Climate., 21, 2283-2293.