Hot News: April sets temperature record

With a premature hot spell, Philadelphia was quite warm in April - and so was Planet Earth in general.

Worldwide, it was the warmest April on record, according to data published today by the National Oceanic and Atmospheric Administration. Based on microwave satellite data, released last week, it was the second-warmest April.

NOAA computed a worldwide temperature of 58.1 degrees Fahrenheit, or 1.37 degrees above the 130-year average. That beat the old record, set in 1998, by 0.09 degrees. NOAA also reported that the temperature for the January-April period set a record, nudging 2002 by 0.02 degrees.

The extent of April sea ice in the Northern Hemisphere was slightly below normal, and about normal in the Southern Hemisphere, NOAA said. But North American snow cover in April was near an all-time low.

That was due in part to a lack of wintertime snow to our north - certainly not around here. Typically, Toronto gets about 2 ½ times the snow of Philadelphia. This season, Philadelphia's snow total, 78.7 inches, was more than quadruple Toronto's, 18.2.

All that local snow did not delay the onset of spring warmth in Philadelphia, which had one of its warmest Marches on record. Then, in early April, the temperature hit a July-like 89.

As for the worldwide warmth, NOAA and University of Alabama scientist John Christy, both cited the influence of El Niño.

El Niño is an unusual warming of the surface waters over thousands of miles of the tropical Pacific, and a strong one persisted during the winter of 2009-10.

The El Niño is now weakening and is forecast to dissipate or yield to its opposite - La Nina, which is a widespread cooling of surface waters.