Summer is the season that gives Death Valley its morbid name. In Summer, average high temperatures are over 110F and lows are over 80F. Visiting the park in Summer is not advisable unless you are adequately prepared with water, sunscreen, and shaded cover. Prolonged exposure this time of year can be deadly.
The best season to visit Death Valley National Park is Winter. Winter brings cooler, more manageable temperatures to Death Valley, and even some clouds! While December and January can be a bit rainy, February and March are a dream.
Death Valley in Spring can be a great time of year to visit – overall temperatures are manageable with highs in March & April around 85 deg.