While Philadelphians may marvel at the sequence of record snows and record heat, the contrast is a mild one compared with what happened in Russia.
Western Russia shivered through a winter that was so cold that the June heat actually was welcomed -- at least at first -- notes a draft report by the National Oceanic and Atmospheric Administration.
What followed was one of the worst climate disasters in history. Moscow suffered through a record-hot July with records falling unimaginably.
It may take months to calculate the heat-pollution-related death toll, but it could well exceed 20,000.
While the disaster has stoked the global-warming fires, the NOAA report was circumspect. It attributed the heat to a presistent atmospheric "blocking" pattern and cautioned against jumping to conclusions.
It said that despite "strong evidence for a warming planet, greenhouse gas forcing fails to explain the 2010 heat wave over western Russia.
"The natural process of atmospheric blocking, and the climate impacts induced by such blocking, are the principal cause for this heat wave.
"It is not known whether, or to what exent, greenhouse gas emissions may affect the frequency or intensity of blocking during summer."
Here is the report.
And here is a fascinating meteorological analysis by the Weather Underground's Jeff Masters.