Many sun-stunned newcomers are surprised to learn it's hotter at 5 PM than it is at noon. As the city pours more concrete and asphalt, the ground retains and radiates heat well into the evening hours. As a result, the average minimum temperature has been steadily rising over the last 20 years. This means summer-evening readings may not dip below 75 degrees. And by 10 AM, the mercury is pushing past 90 again.
Outlying regions can get even hotter.
Lake Mead and Laughlin to the south will flirt with 115-degree days, though they may cool off a bit more in the nighttime. It features scenic outlooks on winding trails and highs that rarely exceed 80 degrees. Evening temperatures dip sharply at dusk. As befitting a land of extremes, the entire southern Nevada desert can get downright frigid in the winter. Low temperatures from December through February will dip below freezing on many nights.