Apparently the Mayans were prone to exaggeration. Turns out 2012 wasn’t the last year ever, but it did rank as the warmest on record for Las Vegas.
The average temperature for the year was 71.2 degrees, two-tenths of a degree higher than the previous record, set in 2007.
And while Las Vegas certainly saw its share of extreme heat in 2012, it was our not-so-low lows that helped set the new mark, according to Chris Stachelski, a meteorologist for the National Weather Service in Las Vegas.
The average low for the year was 60.5 at the valley’s official weather station at McCarran International Airport. That is the highest average low for any year since record-keeping began in 1937.
There is no debate about the cause, either. This climate change was brought on by people.
"It’s all due to the heat-island effect. It’s all due to human development," Stachelski said.
The valley’s average annual temperature has been on the rise since the late 1970s, driven by the proliferation of pavement and concrete where the desert used to be. Stachelski said the overnight lows really started shooting up in the mid-1990s as the booming city soaked up more and more heat.
He doesn’t expect the new record to stand for long. "The previous record was only 5 years old," Stachelski said.
The year also saw several unusually large and intense storms, which dumped enough precipitation to rank 2012 as the 20th wettest year on record despite a below-average number of rainy days. The official rain total for 2012 was 5.31 inches, but parts of the southeast valley saw considerably more rain, including one gauge near the Las Vegas Wash and Pabco Road in Henderson that logged almost 10 inches for the year.
Stachelski said weather was a factor in at least 11 deaths and roughly $75 million in property damage in 2012.
Eight people died from the heat, one from the cold and two from flash floods. They were the first flood-related deaths in the Las Vegas Valley since 2002, he said.
According to National Weather Service estimates, some $50 million in damage came from a single storm on July 15 that dropped quarter-sized hail on parts of Summerlin and the northwest valley, damaging about 10,000 vehicles. The rest of the damage came from a pair of floods in August and September.
Stachelski said large-scale hail damage is "almost unheard of" in Las Vegas. "It’s not like Kansas or Illinois."
With a high of 114, July 11 ranked as the hottest day of 2012. The mercury climbed into the triple digits on 81 days last year, 11 more than normal. The valley saw high temperatures of at least 110 on eight days, which matches the average.
The temperature fell below freezing just three times, all of them in December. The low for the year came on Dec. 20, when the mercury dipped to 30 degrees, ending a record streak of 378 freeze-free days.
2012 was also the warmest year on record for Reno, with an average of 56.3 degrees; Ely, 47.8 degrees; and Tonopah, 54.1. Elko, 49.6 degrees, experienced its second-warmest year on record, while Phoenix, Tucson and several other communities in Arizona saw record or near-record warmth.
Stachelski said global climate change could be playing some small role in the valley’s warming trend, but "99 percent" of the cause can be traced to the growing expanse of man-made surfaces that keep Las Vegas from cooling off at night as it once did.
"The average lows have skyrocketed since the start of record. The average highs not so much," he said.
Contact reporter Henry Brean at firstname.lastname@example.org or 702-383-0350.