April temperatures (preliminary)
Global composite temp.: +0.50 C (about 0.9 degrees Fahrenheit) above 20-year average for April.
Northern Hemisphere: +0.80 C (about 1.44 degrees Fahrenheit) above 20-year average for April.
Southern Hemisphere: +0.21 C (about 0.38 degrees Fahrenheit) above 20-year average for April.
Tropics: +0.63 C (about 1.34 degrees Fahrenheit) above 20-year average for April.
March temperatures (revised):
Global Composite: +0.66 C above 20-year average
Northern Hemisphere: +0.85 C above 20-year average
Southern Hemisphere: +0.46 C above 20-year average
Tropics: +73 C above 20-year average
(All temperature anomalies are based on a 20-year average (1979-1998) for the month reported.)
The most recent El Nino Pacific Ocean warming event might be fading but temperatures in the Arctic hit record highs in April.
April's record high (averaging +2.46 C, about +4.43 degrees Fahrenheit, warmer than seasonal norms) caps the Arctic's warmest five-month period in the satellite temperature record. From December 2009 through April, temperatures in the Arctic averaged 2.07 C warmer than seasonal norms.
November 2005 through March 2006 was the second warmest such period, with average temperatures that were 1.73 C warmer than seasonal norms.
Warmer than normal temperatures have become the norm in the Arctic: There have been only three months in the past decade when average temperatures were cooler than seasonal norms from latitude 60 N (about even with Helsinki and the southern tip of Greenland) to the North Pole.
Globally, April 2010 was the second warmest April in the 32-year satellite temperature record, behind only April 1998 (+0.76 C). The first four months of 2010 were the second warmest start of a year, also trailing 1998.