108 IN THE SHADE

About an hour before the high temperature in Las Vegas hit a record 108 degrees Monday for May 19, Luis Zamora leaned on the rake he was using to smooth over some steaming asphalt on Summerlin Parkway to talk about one of the hottest jobs of the day.

"I drink water every 10 minutes and chew sunflower seeds for salt," the 26-year-old Southern Nevada Paving worker said while a single lane of cars and trucks crawled west toward the Town Center Drive exit.

As Zamora worked at 2 p.m., the temperature read 105 degrees outside a Nevada Highway Patrol car parked a few yards away. But beneath the inch-thick soles of his boots, the smoldering black surface was 125 degrees hotter, or 230 degrees, having cooled off from more than 300 degrees when the truck that hauled it left the asphalt plant.

And it got hotter outside as the day went on, reaching 108 degrees at 3:15 p.m. in the shade of the official monitoring site at McCarran International Airport.

After an hour-long reprieve of a degree or two less, the temperature again hit 108 degrees at 4:19 p.m. Both times the high temperature shattered the previous record of 102 degrees for May 19 that was last reached in 2006, according to the National Weather Service's climate book, which tracks local temperature extremes dating to 1937.

These types of temperatures wouldn't raise an eyebrow in July or August, but Monday's high was one degree shy of May's monthly record of 109 degrees, hit on May 26, 1951, and last tied on May 28, 2003.

National Weather Service meteorologist Chris Stachelski said today's forecast calls for setting a record for May 20 of 105 degrees, surpassing the previous mark for that date of 102 degrees that was last reached in 2005. In so doing, the highest low temperature for May 20, 77 degrees in 2006, will probably be broken with a low this morning of 81 degrees.

That would make three record-breaking days in a row, counting Sunday's 104-degree reading, a new high for May 18.

Records were also broken Sunday in Reno with a high of 96 and elsewhere in Northern Nevada, including Lovelock at 102 degrees.

But a dramatic turnaround is on the way later this week. Stachelski said a strong cold front is expected to move through Southern Nevada on Wednesday afternoon with the high temperature reaching 85 followed by a high Thursday of 76 with a 20 percent to 30 percent chance of showers late Wednesday through Saturday. A thunderstorm is also possible.

What drove the temperatures up this week after a relatively cool spring?

"There's been a lot of hot air up north and northwest," Stachelski said

He explained that a large area of high pressure over northern California and Oregon shifted southward to Southern Nevada and Southern California, where records also fell in spectacular fashion at Death Valley National Park, 100 miles west of Las Vegas.

At the park, the temperature topped out Monday at 120 degrees. The previous record for that date was 114 in 2006.

Monday's high also marked the first time the park has reached the 120-degree mark before May 25, breaking a record dating to 1913. Later that year, Death Valley notched the hottest temperature ever recorded in the Western Hemisphere, a blistering daytime high of 134 degrees.

Park Ranger Charlie Callagan said Death Valley's normal high this time of year is 100, which makes what happened Monday even more surprising.

"That's 20 degrees above normal in the hottest place in the country," Callagan said. "That's scary."

Death Valley also set a new record with Sunday's high of 118. That broke the previous record for that date, a high of 114 that was recorded in 2006 at the park's official weather station in Furnace Creek, Calif.

Back in Las Vegas, the National Weather Service issued an excessive heat warning from noon until 7 p.m. for Monday and today. For residents, that means use common sense and stay out of the heat unless it's necessary to be outside, and limit such activities as jogging and hiking to morning hours when it's cooler.

Likewise, Clark County air quality officials issued an advisory for ground-level ozone through today, saying "everyone should limit strenuous outdoor activity," especially people with heart and respiratory diseases.

Despite the warnings, Jimmy Maddin had to contend with the sun beating down on him after his motor home's engine quit in the midst of heavy traffic slowed by the repaving project on Summerlin Parkway.

"I've had better days," he said while he unhitched the Jeep he was towing behind his motor home.

When they left Williams, Ariz., on Monday morning for Las Vegas the temperature was 52 degrees. By the time they arrived at the Hoover Dam checkpoint, the mercury had jumped to 99 degrees. While they were stuck in traffic on Summerlin Parkway, they and hundreds of other motorists were sweltering in 102-degree heat, heading for 108.

"My dog, my bird, and my wife are in there," Maddin said. "Everything is screaming hot."

Review-Journal writers Henry Brean and The Associated Press contributed to this report.

Contact reporter Keith Rogers at krogers@reviewjournal.com or 702-383-0308.