The desert is very arid which means that you need a lot of water to go their because if you do not go into the desert without water you will die in the mater of hours depending on the annual temperature in the desert. You should wear dry wicking clothing which helps you stay cooler and you won't get hot fast. The best time to visit the Desert in Arizona is in early March. It doesn't get to hot during the day and it also is almost perfect at night. It is around 50 degrees at night and around 75 degrees during the day. In Death Valley it can get up to 100 degrees Fahrenheit. If you visit in March not only will you get good weather you might get to meet a famous MLB player.