March 2009 Tenth Warmest On Record For Global Temperatures

The analyses in NCDC’s global reports are based on preliminary data, which are subject to revision.  Additional quality control is applied to the data when late reports are received several weeks after the end of the month and as increased scientific methods improve NCDC’s processing algorithms.

Temperature Highlights

• The combined global land and ocean surface temperature for March was 55.87degrees F, which at 0.97 degrees F above the 20th century average of 54.9 degrees F ranks as the 10th warmest March on record.
• Separately, the March global land surface temperature was 42.47 degrees F, which was 1.67 degrees F above the 20th century average of 40.8 degrees F, ranking it as 10th warmest March on record.
• The March global ocean surface temperature of 61.42 degrees F was eighth warmest on record, reaching 0.72 degrees F above the 20th century average of 60.7 degrees F.
• The combined global land and ocean surface temperature for the year to date (January-March) was 55.04 degrees F, 0.94 degrees F above the 20th century average of 54.1 degrees F and ranking eighth warmest.
• The Northern Hemisphere experienced its 12th warmest March on record, while the March 2009 Northern Hemisphere average ocean surface temperature tied with 2001 and 2006 for seventh warmest.
• For the Southern Hemisphere, March 2009 land surface temperature was the fourth warmest March on record, while the March 2009 ocean surface temperature was sixth warmest.                   

March Snow & Ice Cover

• Based on NOAA satellite observations, March snow cover extent was near the 1967-2009 average for North America, and below average over Europe and Asia. Northern Hemisphere snow cover extent also was below average for March.
• March 2009 snow cover extent over Europe and Asia was 9.26 million square miles (23.98 million sq. km), which is 0.43 million square miles (1.11 million sq. km) below the 1967-2009 average of 9.69 million square miles (25.09 million sq. km). This represents the ninth smallest snow cover extent for Eurasia in the 43-year data set.
• Satellite-based snow cover extent for the Northern Hemisphere was 15.38 million square miles (39.83 million sq. km) in March, which is 0.40 million square miles (1.05 million sq. km) below the 1967-2009 average of 15.78 million square miles (40.88 million sq. km). 
• Arctic sea ice coverage was at its sixth lowest March extent since satellite records began in 1979, according to the National Snow and Ice Data Center. Average ice extent during March was 5.85 million square miles (15.16 million sq. km), 3.7 percent below the 1979-2000 average. Arctic sea ice usually reaches its maximum extent in March, and retreats to its annual minimum extent during September. March Arctic sea ice extent has decreased at an average rate of 2.7 percent per decade since 1979.
• Antarctic sea ice extent in March was at its fourth-greatest level of the 31-year observational record. Antarctic sea ice extent reached 15.8 percent above its 1979-2000 average. Since 1979, Antarctic sea ice extent for March has increased at an average rate of 4.7 percent per decade.