Think this summer is hot? Get used to it - USATODAY.com

In fact, according to NWF climate scientist Amanda Staudt, the summer of 2010 might actually be considered mild compared with the typical summers in the future. "We all think this summer is miserable, but it's nothing compared to what's in store for us," she says.
...
Staudt concedes that it can't, as does Chris Fenimore, a physical scientist at the National Climatic Data Center, who was not part of the study: "It's not really possible to pin a single event on climate change."

However, Fenimore notes that the frequency at which these extreme weather events are occurring — such as extreme heat or cold — are on the increase.

"Most locations have had about twice as many days with temperatures exceeding 90 degrees than they typically would by the end of July," the NWF report states about this summer's heat.   [Can we see some data to back up this claim?]