SALT LAKE CITY -- Salt Lake City is in the midst of a scorching summer already among the hottest in history.
The city has registered 16 days of triple-digit temperatures this year, the latest coming Tuesday when the temperature gauge nudged up to 100 degrees.
That's already the fifth-most on record for the Northern Utah region that has historically averaged a mere five 100-degree days a year. With a month more of searing heat left, the summer of 2013 could climb up the list.
The record for triple-
digit days is 21, set in 1960 and again in 1994. There have been two summers with 17 days of 100-plus temperatures, in 2003 and 2007.
That means three of the five hottest summers have come in the past decade and four of the five in the past 20 years.
It's the kind of trend that goes beyond normal weather fluctuations and bolsters research suggesting there is global warming, said David S. Chapman, a University of Utah professor emeritus of geology and geophysics who has studied global warming for 20 years.
"We are now approaching things that one would definitely consider to be climate change," said Chapman.
The heat has caused about a dozen roads to buckle and triggered red-flag warnings for extreme fire danger caused by extended stretches of hot and dry conditions. It has been the fodder of water cooler conversations for residents who are avoiding taking jogs or mowing their lawns until late evening when the heat subsides.
It has been a boon for ice cream shops and shaved ice huts set up in grocery store parking lots as customers come looking for cool treats.
This summer's heat can be attributed to consistent high pressure across the West, said National Weather Service meteorologist Eric Schoening. But he acknowledged that the larger picture hints at climate change.
For instance, the annual average of 100-degree days has been eight over the past decade, up from five previously, he said.
"We can't attribute any one season to global warming, but the fact that we are seeing this more and more frequently can certainly be attributed to the fact that, on average, we are getting warmer across the globe," Schoening said.
Globally, it has been the warmest decade on record dating back to 1860, Chapman said. Chapman and other academics have analyzed temperatures taken in hundreds of boreholes drilled around the world to show that average temperatures have been steadily increasing for the past 150 years.
"We're observing more extreme heating, and we will observe even more of them in the future," Chapman said.
The temperatures used by the National Weather Service are taken from a gauge at the Salt Lake City International Airport. Schoening said the temperatures there are generally representative of weather along the Wasatch Front, home to 2 million of Utah's residents who live in a string of cities from Brigham City on the north to Santaquin on the south.
The forecast for the next seven days doesn't call for any 100 degree days, Schoening said, but temperatures could sneak up to triple digits with highs expected to reach 98 or 99 on several days.
"It's not out of the question," Schoening said.
Temperatures traditionally begin to cool down in late August, though Salt Lake City has registered 100-degree days as late as Sept. 8, he said.