Global Temperature Trend Update: July 2011

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Every month University of Alabama in Huntsville climatologists John Christy and Roy Spencer report the latest global temperature trends from satellite data. Below are the newest data updated through July, 2011.

July 2011 was 3rd warmest July in 33-year temperature record

Global Temperature Report: July 2011

Global climate trend since Nov. 16, 1978: +0.14 C per decade

July temperatures (preliminary)

Global composite temp.: +0.37 C (about 0.67 degrees Fahrenheit) above 30-year average for July.

Northern Hemisphere: +0.34 C (about 0.61 degrees Fahrenheit) above 30-year average for July.

Southern Hemisphere: +0.40 C (about 0.72 degrees Fahrenheit) above 30-year average for July.

Tropics: +0.20 C (about 0.36 degrees Fahrenheit) above 30-year average for July.

June temperatures (revised):

Global Composite: +0.32 C above 30-year average

Northern Hemisphere: +0.38 C above 30-year average

Southern Hemisphere: +0.25 C above 30-year average

Tropics: +0.23 C above 30-year average

(All temperature anomalies are based on a 30-year average (1981-2010) for the month reported.)

Notes on data released August 1, 2011:

July 2011 was the third warmest July in the 33-year satellite-based global temperature record, which is consistent with the long-term warming trend seen in the satellite data, according to Dr. John Christy, a professor of atmospheric science and director of the Earth System Science Center at The University of Alabama in Huntsville.

A few regions with warmer than normal temperatures were scattered across the North Hemisphere, including the eastern two-thirds of North America. July's two "warmest" anomalies were in West Antarctic, more or less due south of … Marin County, California. Winter Antarctic temperatures were as much as 5.57 C (about 10.03 degrees F) warmer than seasonal norms there.

July Averaged Global
Temperature Anomalies
   July 1979-2011
 Warmest to Coolest
  (degrees Celsius)

  1. 1998   +0.441  
  2. 2010   +0.419  
*3. 2011   +0.372  
  4. 2009   +0.359  
  5. 2005   +0.272  
  6. 2002   +0.219  
  7. 2007   +0.181  
  8. 2006   +0.147  
  9. 1991   +0.118  
10. 1988   +0.117  
11. 2003   +0.109  
12. 2001   +0.061  
13. 1983   +0.048  
14. 1987   +0.044  
15. 1995   +0.025  
16. 1997   +0.015  
17. 1980   -0.002  
18. 2008   -0.009  
19. 1990   -0.028  
20. 1981   -0.031  
21. 1994   -0.032  
22. 1999   -0.075  
23. 1996   -0.086  
24. 2000   -0.087  
25, 1993   -0.115  
26. 1979   -0.122  
27. 1989   -0.172  
28. 2004   -0.189  
29. 1986   -0.259  
30. 1982   -0.328  
31. 1984   -0.336  
32. 1992   -0.405  
33. 1985   -0.447

Go here to take a look at the monthly data since 1978.