"There usually is a big media story that can define a season," Verrone said in an e-mail to ABCNews.com. "As humans, I believe we tend to try to find themes in life that help us remember and make sense of our lives and our seasons.
"Americans are out of school, they are on vacation, they seem to have more time to take part in activities they might not otherwise have the time for. They tune in more to what is happening around them locally and nationally, and they seem to be open to the idea of a defining theme for that particular summer."
Recalling past summers of note, Verrone said that last summer will be remembered as the season of the presidential election, 1968 will forever be known as the "Long, Hot Summer" and the year before, 1967, is remembered as "The Summer of Love."
And plenty of notable events have occurred in the summers in between. In the summer of 1994, O.J. Simpson's white Ford Bronco attempted to escape the Los Angeles police after his ex-wife and her friend were found dead.
The summer of 1997 was marked for the death of Princess Diana, who was killed Aug. 31 of that year in a car crash in Paris.
More recently, 2001 was known as the summer of the shark because of the attention paid by the media to a shark attack on an 8-year-old boy and then subsequent attacks throughout the summer.
On Aug. 29, 2005, Hurricane Katrina touched down in New Orleans, La., leaving the city underwater and killing thousands.
In August 2007, a Minnesota bridge collapsed, killing 13 and injuring many more.
And, with less than three weeks of summer remaining, Musto isn't sure we've see the last of the celebrity death trend.
"It's been a harrowing summer of sadness," he said, "and one can only alternate between wondering 'Who's next?' and 'Who's left?'"